Its the amount of data being transmitted, and again, your way relies on having something implanted into me to transmit the uploads. Not acceptable by current technology. But the amount of data that can be stored in a chemical matrix is far beyond anything we will ever be capable of electronically. So either we figure out how to make organic computers, which I am against with anything even close to our technology level, or you end up with a download thats potentially Attobytes in size. Remember, your brain can compress 70+yrs of knowledge, sights, sounds, smells, sensations, and memories into an 80Mb package. Unzipped, that file is beyond comprehension in size. Even at near instantaneous download speed, it would still take potentially hours. Hours that I would gladly spend in return for essential immortality. Of course it would all come to an end at some point, whether through my own hand or someone elses, or simply because ive lived to the end of the universe itself, it will still end. But at such time I will welcome said end with open arms, completely fulfilling everything that can be done, learning all that is learnable, and spending millenia pondering questions that have no meaning. Like if the glass is filled to completely and exactly half, to the nearest gluon, is it half full or half empty.
I believe every question has a definitive answer, you simply need to think of it. That is one of the few I can not definitively answer. I know, I drive philosophy professors absolutely batty. I had one in high school that was actually stupid enough to ask the question: If a tree falls in a forest, and no one is around, does it make a sound? I answered yes, and I know because it made a sound when I was around, then went into a 35 minute physics rant on how the only way that tree could fall and NOT make a sound is if you were able to stabilize its cellular structure inside of a complete vacuum environment, and then, inside of the vacuum let it fall. Then and only then would it not make a sound. It was fine until I ended it with "And sir, if you can grow tree's on the moon you should call NASA instead of wasting our time with stupid ass analogies." What can I say, I was angry about being forced to take the stupid class as an elective anyway. Im a no grey area type of person, me and philosophy dont agree.
Edit: And I also fail to see how a persons demise, with such minute, blink of an eye lifespans we possess, could possibly be timely?