I had my Paperwhite online a couple days ago to download some games (which turned out to be crap) and before the games came down, I got updated from 5.3.3 to 5.3.8.

It took a while, but I think I've got it back to where it was, only it's running much faster. I used to have a noticeable delay in Mahjong and Sudoko between when I touched a tile or number and when the PW responded. Now, it's running the way I always thought it should.
(something about clouds and silver linings)