iOS 7
I’m blindsided. Some parts of it are gorgeous, other parts are hideous. The Home Screen icons seem particularly terrible. I can’t make any sort of conclusions on this stuff now. The changes are much more sweeping than I expected them to be. It isn’t just a theme, the OS behaves in new ways, like the fact navigation controllers can be interactively pushed and popped with a swipe gesture. It responds to device motion, for goodness sake.
Rich texture has been drained away almost unilaterally. iOS 7 relies heavily on perspective effects, translucency and borderless buttons to form apps that are hardly recognisable as iOS apps.
It’s different … I don’t know what else to say right now.