I installed it on my iPad Air 2 (As an upgrade from iOS 8.4 Beta 4) just to play around the new features and then I planned to restore back to the previous version I was running since I knew as a beta 1 it would be buggy. My iPad ran pretty hot after I installed it, and the battery drained pretty fast, but then it cool down after a while. Some of my apps crashed on launch, some of the new multi tasking features like split screen are buggy, the picture and picture video is buggy (I couldn't go back to full screen after I put the video in PiP mode) etc. as I expected a beta 1 to be. So right now I'm restoring back to iOS 8.4 Beta 4 which has been very stable for me. There isn't much terribly exciting for me in iOS 9.0 unfortunately (except maybe the system optimization) so I can wait for the release version in the fall.