"As to whether an exact copy of you is actually you, I would say yes, unless you're going to argue something supernatural like a soul"
No you are confusing same subset of object with identical object. This is the same as with the teleporter dilemma. If you take somebody then construct a copy of all neurone and then murder the original, nobody may even tell the difference. But from the perspective of the person you murdered : they were killed, life stopped. To hold that that person would continue in the copy is to hold belief worst than supernatural. This is the difference between identical subset of object (same copy of you, same copy of a basketball), and same object (if i take a basket ball or human, copy it atom by atom and destroy the original).
The problem is that many (most?) people do not care that an identical clone continue in their place, what they want is that they continue forever. And THAT is why the complete upload in an instant do not achieve the same goal as the bit by bit hardware replacement and integration with the system. In fact think of it as this : imagine the upload system is non destructive. You have essentially the hardware copy working while the human is not dead. See the problem ?