I went from 8.1 to 10 pretty much on the first day of availability. My gaming system came with 8 pre-installed, which with the addition of Classic Shell, I found to be better than 7. It then got upgraded to 8.1 and as I said, 10.
Something's wrong. I can backup my 600GB on my system drive in under an hour with AOMEI. I don't ever do the check. I always do full backups. I have never even tried the incremental thing.