The current iOS 8 is the best of what Apple can do. Its fast and so smart but the UI on it is almost 8 years old!. Yes you could argue that Apple changed that in iOS 7 a year ago but the changes is almost about the icons and the colors, No significant change happened nor the way you interact with apps on the home screen. But when Apple revealed the Watch months ago, They somehow leap forward to a new UI design which I think will revolutionize the iPhone/iPad experience. Apple needs tons of courage to do that because its going to be the biggest change Apple will do in the history of its mobile devices. If Apple done that in iOS9 will you like it?