I'm with McCoy here

Because it's still a copy, so you still die. Imagine if there was a delay between the copy being produced and the original being destroyed, long enough for them to see each other if transported within the same room.

To Be

Jesus Christ, existential crisis for the morning.
You are a different person than you were yesterday.
You have all sorts of new and different experiences from that person.
You're even a different person reading the last word in this sentence, than you were when reading the first.

But you're no less you, are you?
- spoiler
  
  asdfasfasfasfas
  
  Yes! Great movie!
  
  spoiler
  
  That machine was much more than a transporter. It didn't have to destroy the matter to duplicate it.
  
  Angier was stupid to keep killing the other versions of himself. He could have created a much better trick, being in several places at once.
  
  And they each would have felt they were the original Angier. Who could say they were wrong? They all were, and are still, the original. Just different versions of him, with different experiences. No different than you, being the same person who was different yesterday than you are today.
  
  spoiler
  
  asdfasfasfasfas
- You are a different person than you were yesterday.
  
  In some senses, yes. In other senses, no. Since my birth, there has been an uninterrupted set of reactions between neurons in my brain. Individual neurons may be added or removed, various inputs and chemicals may change this reaction, but this ongoing reaction between them has never stopped. If you show me another person with the exact same pattern of neurons in their brain, with the exact same pattern of reactions happening within it, then they are for all intents and purposes a perfect copy of my mind. But if you shoot the me that's typing right now in the head, then the me that's typing right now doesn't get to see what happens tomorrow, even though for all intents and purposes there is still a starman2112 in the world.
  
  But the Starman typing today, doesn't get to see tomorrow any way. They get replaced by the next Starman.
  
  I fundamentally disagree. As I said, my mind is a continuous ongoing process of reactions between neurons in my brain. Even while I'm asleep, this process continues. Even as neurons die and are replaced, this process continues. I am the same starman that I was yesterday, and that I will be tomorrow.
Human body replaces most of its cells on average every seven years. So we all already a copy of someone else from 7 years ago.
- That's getting into ship of Theseus territory which is similar, but slightly different than the transporter paradox. It gets closer when you do the whole build another ship out of the replaced parts thing, but with the transporter there's something that gets destroyed and that something is where your consciousness is.
  
  Even a "perfect" copy is still a copy, and the fact that the second consciousness doesn't rely on the first to exist (they could simultaneously exist ala William Riker) it's a separate instance so a separate person.
- No, we replace our external skin cells and blood a bunch of times but our major organs and muscles stick aroubd.

But is the copy me from my conscious point of view? I don’t care that it looks the same externally. Will I still be inside the ship?

It mainly depends if you believe in a soul that is never copied that makes it "you", or a purely mechanical view of consciousness that says if all parts are copied there is no difference.
Yes. The copy is you as far as it can tell.
And the original you doesn't exist anymore to be able to tell anything.

So "you" continue, from your point of view.
- no.. that's not sufficient. There's a new me that was not me that is now me, yes, but the original me is gone. Story ended from my point of view, from the new me's point of view it was all fine but they will end in the next transport.
  
  If it can be undeniably proven exactly the same as sleeping or anesthesia, fine. If consciousness provably persists all the way from de-materialization, transport, and re-materialization, like Lt. Barkley. fine. But if there is any doubt that consciousness ends, and a new consciousness is created, that is where the problem lies, and why many, like McCoy, won't use one willingly.
  
  But consciousness doesn't persist through sleeping or anesthesia. It stops, then starts again some time later. The continuity of memory seems persistent to the consciousness, so it can't really tell the difference. Because it would be impossible for a consciousness to perceive it's own down time.
  
  And it's not really accurate to say a new consciousness is created. It would be more accurate to say the same consciousness is recreated.
  
  I'm not trying to be combative, just to illustrate the point: "cite your sources."
  
  Definitive research is needed.

From an outsider's point of view sure, but does your consciousness dies when dematerialized, only to have a copy of your consciousness going on in the rematerialized body as if nothing happened?

That is only an actual issue when you are some sort of spiritualist. From a materialist point of view, the entirety of you is "just" a very complex interplay of elementary particles.
- I don't think this is true. Even if consciousness is only a product of our physical bodies, there's still the issue of who's experiencing it.
  
  When this body dies, I'm dead. I don't care if there are a million other perfect copies of this body or my mind out there, if this mind won't be the one to experience it.
  
  A copy of me can be fundamentally perfect, but simply as a product of being physically separate meat our consciousnesses will be separate. If instead of teleporting, both perfect copies stayed alive and had a chance to talk to each other, this would be apparent. I will continue to experience life from the eyes of my old body, not the clone. We could then go on to live our lives separately, and we would diverge. Because we'd both be separate simply by the physical nature of our existence, we're not interchangeable, and it wouldn't make sense to kill one of us and assume that now it's "teleportation". We didn't see out of the other's eyes before, so why would we see out of the other's eyes when we're dead? No, we'd just die.
  
  The only way I can see this not being an issue is if the awareness somehow transfers, which requires some sort of technomagic beyond our comprehension, or outright rejection of the existence of consciousness, which is a bold claim.
- It's true that the entirety of a person is "just" a very complex interplay of elementary particles, but I don't think it's only an actual issue if you're a spiritualist. I'm a naturalistic determinist, there's no such thing as souls or spirits.
  
  My line of thinking is this. Let's say I step into the machine, and it makes a perfect copy of me at another location, but fails to dismantle my body. Since we're talking about the transporters in Star Trek, there is precedent for this happening. I step out of the transporter entrance, and another me steps out of the transporter exit. I don't see through that person's eyes, I don't hear through that person's ears. They are separate entity, no matter how similar they are to me.
  
  If the transporter had successfully dismantled me, I still wouldn't see through that person's eyes or hear through their ears. I would be dead. Another person with my memories would step out of the exit. As far as the rest of the universe is concerned, that person is me. But I don't care about the rest of the universe, I care about my own brain, which has been destroyed. Why would I agree to be transported, if I don't get to see what happens after?

ITT people who think they’re only themselves only if they’re completely continuous. Any number of them could have been replaced with a clone while sleeping and not know the difference. I am me, and that’s all the matters to me.

Of course I wouldn't know. But the former me who got dragged off is dead. That's the whole point, the clone has no way of knowing and simply continues on life while the original dies.

And because we only exist in the present, we rely on our memories of the past to tell who we are. Our memories tell me I'm me, so I think I'm me.

Maybe it doesn't matter to you, but the reason I don't want to die is because I want to be aware. If I am never conscious again, but a copy of me is, good for them I guess, I wish them the best, but it's not what I want. I'm not conscious of waking up in the morning, even if they're me. I'm dead.
- And you would have known you’d been swapped how? What if someone came up to you and said that they have irrefutable proof that you were replaced with a clone of yourself a few years ago. How would you know the difference unless told. And even once told, what does it matter if you can’t pinpoint the exact day?
  
  If it already happened, there's nothing to be done. But if I find out that there's a thing that I'm doing every single day that's killing me and making a copy, I'll simply stop doing that thing
  
  I guess that’s where I’m confused like OP is. What difference does it make at that point? You’ve been going through it countless times, nothing has changed, you were no different, so what does it matter?
  
  It’s like the people that are anti-vaxxers, they’re freaked out with no basis that “it’s changing who I am!” even though there’s plenty of evidence to the contrary (I would assume general transporter tech wouldn’t be available to the masses if it wasn’t in this scenario)
  
  Strictly speaking, I've never used a transporter before. It's important to nail down specific definitions and concepts here. What do I mean when I say I? I'm referring to the human using the alias starman2112; the individual entity typing right now. I've gone more in-depth in other comments, but essentially I am the ongoing chemical reactions between the neurons in my brain. This reaction has been perturbed, interfered with, but never stopped.
  
  In what way am I still "me" after being transported? I'm precisely the same person, right? But I'm not. I'm a perfect copy of the last person. Say the transporter failed to dismantle him when he stepped into it. Does he see what I see? Hear what I hear? No. We are separate people. So if it had dismantled him, would he see what I see, hear what I hear? Still no, of course. He's gone. He doesn't see or hear anything anymore.
  
  Now that I understand that, despite having countless memories of stepping into and out of transporters, how could I possibly bring myself to step into one "again?" In reality, it would be the first time for me, and I would be dooming myself to never see or hear again, unless it malfunctions and fails to dismantle me.
  
  I don't appreciate the comparison with anti-vaxxers. The problems with transporters are not based on lies or incorrect assumptions, it's based on the fact that it kills you and creates a copy.
  
  It only matters in that a person died. A person with their own subjective experience that they no longer get to experience. It doesn't matter that in this case I inherited their memories, and it doesn't matter when it happened other than out of curiosity. I'd mourn them the same.
  
  And as for how I would know... If I'm the clone? Obviously I would never have any way to know, short of someone coming up to me. On the other hand if I were the original, I would "know" because I would be dead. (Or rather, I wouldn't know anything, because the dead don't experience or think)
  
  Edit: It matters that I inherited their memories in that it might influence the way I see the world, my identity, and their death, but it wouldn't change the fact that I mourn them. I am a distinct person from other versions of me, regardless of whether I'm a clone or they're a clone, and if they die it's just as much a tragedy as any other human death.

A copy isn't you, it's someone else, a clone. It means you die when you step into the teleporter and someone else takes over your life.

But a perfect copy is more like the you who stepped onto the pad, then then you are like the you who went to sleep last night.
All sorts of changes happened, while you were sleeping.
All sorts of changes happened while you were typing your last comment.
The you of now is a very different person then the you of 5min ago.
- But I have the same consciousness
  
  So does the copy
  
  Fundamentally, no. It doesn't matter if the copy is identical in every way, it's physically separate.
  
  The fact that one is the "original" and one is the "copy" doesn't matter. The fidelity of the copy doesn't matter. It's literally just the fact that it's different meat.
  
  The copy will believe it's me, and will for any outside observer be identical to me, but I will still exist as a separate entity. Up until the next instant, where the clone-and-kill machine enters the next phase, kills me, and I'm gone, and there's a new copy of me out there with a new consciousness, living my life. But the version of me who was me is dead.
  
  What happens if it doesn't kill me instantly? What happens if I get to look my transporter clone in the eyes? We won't have the same consciousness, we'll have two separate copies of the same consciousness. And then it kills me. And I watch myself die.
  
  Yes. You watch yourself die, and you continue being you.
  You're always doing exactly that already.
  Every moment of every day. You replace yourself, with a new self.
  
  Except the person who died is dead, and they stay dead. The person who died's final moments will be seeing their clone standing over them, and their memories will diverge.
  
  They're clearly different meat, different consciousnesses in that moment. They won't know what the other is thinking, they will have to speak to communicate.
  
  How are they not separate people in that moment?
  
  They are separate individuals.
  They are also the same person.
  
  Identity and individuality don't need to be linked. Neither is dependent on the other.
  
  Exactly. Even as a new me lives on, with the same identity, it isn't the same individual. The Me who walked into the teleporter will die, and never wake up again.
  
  I don't care about the continuity of my identity, I care about the continuity of my consciousness. My identity changes over time, but it's always Me who experiences that identity.
  
  I would rather have my identity radically change, but continue to be the one to experience it, than have my identity continue, but have it be a part of a different consciousness.
  
  Your consciousness is always different. Ever changing. Never fixed.
  In fact it's the change in your consciousness that inspires an change in identity.
  
  Think of it like this. I have a computer hard drive. I can make a perfect clone of this computer hard drive. Every single one and zero accounted for on a separate disk. While these hard drives contain the same information, changes to one do not cause changes in the other. While they contain the same data, they are not the same hard drive.
  
  If you have two drive in a RAID 1 array. They have the same data. If one dies, it doesn't matter. Everything important is preserved without interruption.
  
  But I'm not in a RAID array with my teleportation clone. As far as the data contained within my brain goes, nothing is lost if I die the very instant that my clone is made, but I posit that what makes my mind my mind isn't just the data held within it.
  
  There's a part of my brain that argued with itself when it reread that, because if the ongoing chemical reaction is what makes my mind my mind, then if I were cloned a la Farscape season 3, then both starmans have claim on being the starman. Even then, I feel like that only helps to illustrate the fact that my mind is both the data and the uninterrupted chemical process. If both clones are made of the same ongoing chemical process but have different data in them, then they're not the same starman as each other, even if they are the same starman as they were just before the cloning.
  
  The data is what makes me the starman that I am right now, while the ongoing chemical process is what makes me the starman that I was yesterday, and that I'll be tomorrow. Good talk, I love a discussion that makes me further my own opinions on personhood

It's like VHS!

Then it's not perfect.
- Betamax, perhaps.

Because you won’t be the copy, the copy will be the copy.

From the copies point of view, it is you.
- But I'm not looking from my copy's point of view, am I? And if you posit that I may be the copy in the first place, then the original isn't looking from my point of view.
  
  Both feel they are you. And it's only one point of view, during the time you both exist, that's lost when one of you dies. The second you persists.
  
  Both my clone and I feel like we are starman, but both of us would acknowledge that we are not the same starman. We're two almost perfectly identical sets of neurons and chemical reactions between those neurons, but even ignoring the fact that we stopped being identical the moment we start receiving different inputs from our senses, the fact that we do not occupy the same space means that we are separate entities. If one of us dies, they don't get to keep living on in the form of the other.

Imagine the machine makes one such perfect copy of you without successfully dismantling you. That person stands in front of you. Do you see through their eyes? No. If you die, do they die too? Of course not. It doesn't matter how perfect the copy they are, they are not the same person as you. If the biological processes in your body end, you die. The you that steps into these teleportation machines never gets to see what happens on the other side of them.

And that happens naturally all the time.
The person you were yesterday, or even a minute ago, never gets to see who you are now.