Found a really strange, only slightly annoying bug. If you open an app that is in an app folder on your home screen, use the app for a bit, then press the home button to return to the home screen, then press the home button to close the folder, the folder takes about 2 seconds to close. Like the phone is thinking. What's strange though is that if you tap the space around the folder rather than pressing the home button to close it, it closes instantly. I guess I'll have to retrain my fingers to do that.
I noticed that too. Started in beta 2.