iOS 9 isn't what I thought it would be. Apple promised smoother animations and better battery life. I'm not seeing either. Sorry, Apple. Control Center is much smoother on an iPhone 5 running iOS 8 than an iPhone 6 running iOS 9. I don't understand how Metal was implemented and everything just got worse. Hopefully they clean up a ton for the GM because right now I'm not seeing it. I will do a clean install when iOS 9 goes public though so let's hope that fixes things. Public Beta is everything but clean.
Anyone else notice how spotlight lags and hangs a lot more since iOS 9 beta 5 (PB 3)? Especially if you slide up and down really fast it hangs right in the middle of the animation. Also, sometimes the Siri suggestions appear but nothing else blurs then you get stuck in spotlight and it won't go away. The app switcher is stil causing frame drops on both my iPhone 6 and iPad mini 2, however it's better than it was before. Exiting and entering the switcher is where it is most problematic, and even sliding away apps is a little laggy and scrolling drops frames too. It's a mess. On iPad if you hold two fingers on the keyboard and let go, it gets stuck in trackpad mode.
These have existed since early iOS 8.0 betas, some even in iOS 7: Splitting and moving the keyboard still causes the non letter keys to turn dark gray and it lags and stutters and has graphical artifacts. Popping up split keyboard is weird, it is connected for the duration of the animation and then it snaps back to being split. Rotating App Store stutters, rotating spotlight stutters, rotating keyboard stutters, control/notification center over keyboard stutters, control/notification center over open folder stutters, rotating slide to power off screen stutters... There are a ton of totally random stutters that are sometimes there and sometimes not mixed into the mess. Nothing feels consistent, and it makes the OS feel unpleasant or "fragile." "Don't do this! It'll lag and drop frames. Do it slightly different instead so it doesn't look so bad." That sort of thing kind of goes through my mind all the time when using iOS. Best example is scrolling, or putting the keyboard away before you want to rotate your device, use control center, etc.
I have made over 50 pieces of feedback, and everything bad I've mentioned in this post has been sent to Apple. I don't care if it is being nit-picky, it damages the experience and I firmly believe that that matters just as much as glaring bugs, like no Siri Suggestions appearing in the search pane to the left of the home screen. Let's hope that Apple finally realizes this again, and makes iOS as smooth and dependable as iOS 6 was in the end.