Do not upgrade a mini 2 to IOS9. When IOS9 GM came out, I tried it on my mini 2 (previously had IOS 8.1.2).
It turned a perfectly good tablet with butter smooth animations, transitions, web browsing and app loading and stability it to utterly a complete disaster.
Gave it 3 days and could not deal with the lag, slow fps animations and transitions, 1-2 second delay when you touch clicked an app just for it to start and load. Then there were longer load times for apps because they're optimized for IOS 8 not at all for IOS 9. Since the mini 2 has A7 processor and less than a gig of ram for useable memory, IOS 9 cannot stay loaded into ram to keep things smooth because there is not much of it.
I play Beach Buggy Blitz Racing (first one that came out) and it warns you when there is low memory before continuing into the game to play it. Never saw that error ever before in IOS 8. I even had everything in the task switcher closed out (which by the way lags as well). In IOS 9 I got the low memory error in game.
In game I would get pauses/freezes which is called "hitching" every random amount of seconds.
Crossy Roads loads in exactly 12 seconds for me on Mini 2 and Air 1 using IOS 8. On mini 2 with IOS 9, it took over 30 seconds every single time to load it even after 3 days for the OS to settle.
Also the new IOS 9 keyboard likes to lag and cause all kinds of problems while typing on it because it has more functionality that is automated.
Keyboard on IOS 8 is more simplistic and I can type way faster on it because it keeps up (using it now on my Air 1 running IOS 8.2)
All you will gain in IOS 9 is the side menu app load where you can use apps that support it on side of screen, but main app in main big window on screen is paused and your locked out of it until you close side screen loaded app.
Also you get PiP video which is cool but not worth it to lose performance and basic smooth functionality like in IOS 8. Also tested several times, my Mini 2 would only last 11 hours screen on with usage.
When I restored my mini 2 back to IOS 8.4.1 using the DFU method then restoring iCloud backup, everything was smooth and perfect again making it feel like a brand new top of the line device compared to the messy IOS 9.
Also there is a IOS 9 bug that won't let you login to your Messages and FaceTime apps, no work around and your stuck without it. Also now there is a glitch with Game Center where it does not work when in the main application and lags in game while loading along with game being played.
Trust me it's not worth it, besides in IOS 8.4.1, 30-40 percent gaming, 50 percent web browsing, and 10-20 percent YouTube, music, and networking tools my last usage time with screen on was 13 hours and 15 minutes before 1 percent battery automatic shutdown.
Remember this, IOS 8.4.1 cannot be downgraded to now. Once you go with IOS 9 and realize you hate it like the majority of Apple users across the board (all Apple devices) your stuck with a paper weight that you got to sell.
Just wanted to warn you, my Mini 2 and Air 1 work perfectly on IOS 8 and I want it to stay that way. Never had a single app crash, reload, reset or lockup making device unstable and having to shut it down or reboot.
On IOS 9 did have those problems on mini 2.
Thanks guys,
Sounds good. I just ordered a mini 2 for now and will upgrade it to 9. Next year hopefully when the next one has 3D touch I will upgrade.
Cheers