So in 2014 I bought 6 Plus (because of the bigger battery). It was the newest and freshest model but there was constant lag and stutter in UI of iOS. Few months ago I bought iPad mini 4, which is also the newest model, however, iOS does stutter too! Can somebody explain how can Apple still get away with that? I was laughing at android based devices as some of them lagged even if they were new, but now I realise it is the same with iDevices.