Q: Xamarin.iOS app - slower on iOS10 than iOS9 Our app has some performance issues. One particular area is the opening of a UITabBarController.
I have tested the app with Debug and Ad-Hoc builds built with VS 2015. I am using


*

*Xamarin 4.5   

*Xamarin.iOS 10.10.0


I am testing on real devices


*

*iPhone 6 iOS 10.1.1

*iPhone 6 iOS 9.2

*Pad Air 2 iOS 9.3.1

*iPhone 5 iOS 10


I am seeing consistent and significant performance gains from the iOS 9 devices.
With the Ad-Hoc build, opening of the view, with a large dataset, takes just under 6 seconds (5.8). Opening the same View with the same data and same build takes just over 1 second on the iOS9 devices.
Can anyone suggest why iOS9 would be performing so much better? 
We do not have anything that runs on iOS 10 only. The closest we have to that are calls like this: 
if (UIDevice.CurrentDevice.CheckSystemVersion(9, 0))

However that check would return true for 9 and 10.
