Open up your phone app on Favourites, Recents, Contacts then click on "Keypad" there's a little lag for the Keypad to come up. I don't know if this happened when I was on 9.1, just noticed this, I am on 9.2. Quite angry cause this happens on nothing else. Not sure if this happens on anyone else's or just mine. It's very annoying when trying to call someone very fast.
Bugs I encountered in iOS 9.1 1. Turning on/off the cellular and clicking back rightafter makes it lag 2. Manual screen Orientation isn't working 3. No animation at all after loading heavy game like MC5, turning off will turn back to normal 4. Personal Hotspot sometime detected sometimes not 5. Animation sound is irritating when headphone is plugged/ paired(bluetooth)
I updated my both my iPhone 6 and iPad Air 2 to iOS 9.2 public beta 4 earlier today and I noticed right away that the spotlight search bar was noticeably smoother and my iPad had a problem with the app switcher. Returning to the home screen from the app switcher was very choppy and stutters when I had 3 or more apps suspended. Now it's buttery smooth!! NO MORE LAG!!!! Doesn't matter how many apps are suspended it is buttery smooth!! I'm VERY impressed!
Just another tip I found for 9.1. When in the fingerprint settings press your finger in the fingerprint reader and it will show you what fingerprint number it is. If my thumb is finger 1 and I press my thumb down it will flash Finger 1, just makes it easier to tell which finger is which u have created. Useless but good to know
I have 9.1 but it really lags sometimes on spotlight search and sometimes messages jam and hang a while. Sometimes the device also lag and hang a while. Not sure why as I have much space. It really need to fix.