there is a difference between Dematerialize and Vaporize.
To any outside observer, you'd be right. They would all see a perfect copy appear, talking, thinking and acting just like the original to the point of even believing it
was the original. There's another sci-fi short story whose title escapes me at the moment, but basically it's the adventure of some Space Man, who has successfully used the teleporter 215 of times previously. Only this time "Space Man 216" uses the teleporter and ends up in the afterlife, instead of his destination like he remembers happening before, and finds 215 other identical Space Men already there. Oops.
That's what he said, think about it for a second. What happens when you dematerialize every atom in your body? You die, you have been completely destroyed. It's no different than being chopped to pieces by a sword, even if you had been assembled correctly in another place you would still be dead. In reality, you would enter the transporter, die instantly and then your corpse would appear on the other side. Star Trek's clone and memory transfer (essentially anyway) is really the only transporter theory I've heard that makes any kind of sense.
The other way of doing it, which at least wouldn't murder you every time is by using pocket dimensions, that's how WoW handles heartstones for example, you travel through another dimension incredibly quickly, making it seem like you have teleported. Allthough granted WoW has magic, so trying to explain anything there with science is kind of a lost cause, the argument "It's magic, just go with it" is a little easier to justify.
Right, although I dunno if pocket dimensions would cut it. The only way a mind transfer could occur without the accompanying deletion would be if the "mind/consciousness/soul etc" somehow exists 100% independent of the physical structure that houses it in some kind of meta-physical dimension/space (religious implications aside) and we use technology to basically "possess" a new body through psychic/mystical means. That's heading more into fantasy territory rather than sci-fi though.
Again though,I can't say I'm convinced that our brains' supposed lack of bandwidth is what would be slowing us down in the fight against the robots, necessitating this whole mind-transfer concept in the first place. If anything it'd be our weak bodies that are the problem first, which as I said before, could be vastly improved through genetic modifications and regular cybernetic augmentation; assuming the machines can't take control of our cybernetics, which would seem like a serious issue if we all had cyber-brains. Isn't that the premise in Ghost in the Shell anyway? Hackers taking over the cyber-brains? Seems like we'd want to avoid that eventuality in a fight against AI. :shrug: