Few things I've noticed:
> Brightness is sketchy on iPad 2.
> Shutdown spinner is Retina
> iTunes Trailers crashes on iPad.
> Calendar now shows current date in Notification Center.
> Splash screen for maps still shows 3D button on iPhone 4 even though it"s not enabled.
> Battery life is eh, not really too much different.
> Some pics in Camera Roll are black or corrupted (also happened in iOS 5 beta) on iPhone 4. However, the lag in rendering and sharpening photos when swiping is now almost instantaneous.
> I hope this is a bug: when using volume buttons with screen locked and music playing (whether through headphones or not) the screen lights up to show the volume popup. Every. Single. Time.
There's a lot more, but that's what I've seen. Overall, I'm very surprised at the stability of this beta and it is actually perfectly fine for daily use. Also really happy with all the little things they've changed - makes my life a lot easier.