I downgraded to 9.3.3PB when two weeks came and went with no update. I was having issues with emails not loading in the stock mail app (fixed in beta 2) and other miscellaneous visual glitches. I'm also in the process of rating all of my music and was really irritated that such a basic feature was left out.
Updated immediately after seeing beta 2 had dropped. Still no option for ratings in stock music app but I've gotten around that with a (hideous) 3rd party app for the time being. There's a lot in iOS 10 that I became attached to without even realizing it.