As far as you know. You wouldn't know what they modified.

Id be more fine with not remembering but to each their own

Would you be cool going into the execution chamber and getting shot to transport yourself? Would the memory of the death make a difference, or the ability to visit your previous remains? What happens if there is an accident and the new you wakes up, but the execution chamber fails and the old you is still alive?

If you don't mind there's no problem, of course, but quite a few people want to keep living. If you told a terminally ill person "so you'll die, but don't worry cause we can clone you and tell everybody you got better" I think "oh well then no problem" wouldn't be a universal answer.

Because I don't really care about what the copy can do and think, because I'll be dead. My self disappears, even if someone else has a copy of it.

It's a "I think therefore I am" kind of thing. I know I'm the same person I was five years ago, just with some new memories, and some memories have faded. But I am still the same person.

I don't know whether you are the same person you were five years ago.

The show "Earth 2" in the 90s had an interesting concept in the backstory where not every human had a soul, and they made a device that could detect whether people had souls. I sometimes wonder if that's the case, not everyone is actually a sentient being and just a biological machine.

Of course there's no way to know, so we have to assume that if someone is a human, they are sentient. Same logic as the TNG episode "Measure of a Man", but it applies to humans just as it does to robots.

His machine would not work very well.

Actually, now that I think about it, it's far worse than that. If a company has a teleporter that can build a copy of you, they can also build an almost-copy of you. Say, a copy that is less rebellious. More obedient.

Yeah, the idea's cool in fiction, but in reality I would never touch a machine like this. I will walk my ass over in analogue.

That feels like a very different statement than saying you don't mind stepping into the teleporter knowing you will die while a copy continues from where you left off on the other side.