I'm gonna go fill it out any one of these days too. I have a few different and very weird issues with the new driver. Had it with the release candidate too. Going into BF4 with DX mode, It somehow locks the gpu frametime to the cpu frame time and thus vsync, making it really really choppy, alt-tabbing out into windows and back in again, suddenly it releases and the gpu time drops much lower to what it should be and then smooth delivery is resumed.
The other is even more weird, It hardlocks the comp, but first off, it's when playing BF, it draws up a jagged edge random colored pattern on the screen, then it takes a minute or so before the comp hardlocks, but before that, voice and everything works behind the screen. Weirdest thing is that the mouse-pointer are perfectly normal, so my guess it that it's a Mantle memory leak/bug that happens after an hour or two of contunual gaming.