On my mini 4 with IOS9 340 build, Crossy road takes exactly 20-30 seconds to load to the hippo blue thing animation before you get in game.
On my Air 1 and mini 2 using different IOS 8 versions, both load up Crossy roads in 11-12 seconds flat side by side. And yes on mini 4 stutters and frame drops more than iPads on IOS 8 in Crossy roads.
Also I play "Commute" and in game on section 5 with rain and added graphic effects using the A8 in game, it's running at a way lower fps than compared to on mini 2 and Air 1 using the A7 although without added extra graphic effects. It's choppy on IOS 9 on mini 4.
Now get this, I did test drive IOS9 build 340 on mini 2 for some days. All the same delayed app launching, then delayed loading times, then more choppiness in games with lower fps with a lot of "hitching" in games making the graphics and gameplay go from smooth to big hit in fps then smooth again off and on.
Games affected on mini 2: 8 bit ninja, beach buggy blitz, commute, Crossy road, dead trigger 2, legends 2, trials frontier.
So I did a DFU in iTunes on mini 2 back to 8.4.1 it originally had 8.1.2, restored most recent iCloud backup and everything cloned back to the way it was like on my Air 1 and on mini 2 everything is smooth, instant, no lag, no delayed launch apps, loading times instant or as fast as A7 can load apps, and my best usage time everwith screen on whole time was 13 hours and 15 minutes with 50 percent gaming, 25 percent safari, and 25 percent YouTube and misc app stuff (mini 2).
With mini 4 on low brightness, 30 percent gaming, 50 percent safari, 20 percent of YouTube, music and other misc apps, I can only get 10 hours 37 minutes so far of battery out of mini 4. I think IOS 9 and all the new features to include multitasking and split window which is enabled by default to include video PiP mode, while the mini 4 idles or has any load there is extra pressure on cpu to work more and killing off battery.
Also if Safari uses metal API like Apple claims the whole OS uses it now for everything, it's probably draining this thing dry.
I really like the mini 4 over the mini 2 and think this is a great companion for my Air 1. If battery life does not get better and there are going to be issues with gaming and apps in general if they implement thinning or not, I would rather stick with the older models and IOS 8.x!!!
Last week another poster here noticed frame rate drops in certain games. For example, he mentioned Crossy Road. I can confirm that there are occasional hiccups in that game on my Mini 4.
However after a week, I have played a few more games, and have noticed more frame rate drops.
For example, Sword of Xolan will sometimes become a little choppy (looks like it's dropping from 60fps to 30fps). Also noticed similar choppiness in ShadowBlade.
I have tried various settings changes, including turning off most background refreshing of apps. The framerate drops still happen.
Anyone else notice similar performance issues during games or other graphical apps? I think the Mini 4 hardware should be capable of running these games at a constant 60fps easily, and can't quite figure out why it's doing this.
FWIW my Mini 4 is updated to iOS 9.1.