Sometimes my custom keyboard disappears (using SwiftType). Numeric unlock in Cloud Magic doesn't work; I have to close and reopen. I have 2 apps with swipeable photo-galleries that get "stuck" and cant' swipe (one of which has released a big iOS 8 update and still has behavior). (These may be app issues, not OS necessarily, but that's mostly irrelevant)
Exact same here, I'm using Fleksy keyboard app and it sometimes just disappears; and Redditur's swipable photo gallery gets stuck.
It's very buggy. I installed the GM and fully expected a second GM because of all the bugs I saw. But nope, they shipped it.