Phone is settled down but then the weird animation stutters randomly creep in, apps launch slower.
I honestly cannot stomach this sort of regression in a one year old phone. I'm scrambling to get back to iOS 8 and hope my back up is going to work.
iOS 8 was a mess on launch too and I think this about my last rodeo with an iPhone. Way too expensive for this sort of nonsense.
I always wait until the ".2" version. 9.0 is still a beta version, basically.
I also make sure to do a clean install going 1 full upgrade higher (like 8 -> 9).
I don't like how they do this, either, but that's the deal.