To all--I did the Public Beta--maybe we should have a forum for that--or link it to me! I just started posting/reading in the iOS9 one, sorry!
Public beta is just like updating your phone...it put all of my apps back on, my background image, all settings, and even my health info (I believe because I last backed it up, although on my computer, encrypted).
I haven't run into any issues yet. Actually I did--I was on phone, and it wouldn't turn the screen back on when removed from my face...but when I did it a second time (phone to head, then away again) it showed up.
It's all good!