Personally i've just made the jump back. Ordered SG 64GB 6S today. I've had a S6 Edge since around December 15 and i've given it (and myself) time to adjust and although Samsung seem to have nailed the screens and the ability to customize is second to none. It just isn't iOS! Having watched yesterdays WWDC - iOS 10 seems to be a decent enough reason to add to the switch back list..
The OS has Lagg, Ads on apps or whilst i'm doing something important ads pop up. The App Store isn't trustworthy enough for me. The screen is a bit too big for me in comparison to iPhone having sat the S6E next to it in the phone shop... 6S/iPhone in general (non plus) seem to be a nice size.... and when alls said and done means i can come on here and comment with relevance hahaha Although Mrs B would say i never talk with sense let alone relevance ;D