I've not had many actual buggy issues with iOS 10 lately (except with 3rd party apps that haven't updated to support it yet), but I'm not sold on some new UI/UX changes on iPhone itself. I'm going to reserve judgement until I use it on an iPhone 7 though - I think a lot of the changes I'm struggling with relate to the way the new home button and 3d touch work, which I don't have on my iPhone obviously. Seems to look/work really well on iPad though - I like some of the new layouts when used on the iPad.