Nothing that I absolutely hate, but I do have a couple of suggestions.
Firstly, I think Control Centre would have been better off as a tab in the Notification Centre. I personally don't see much use for the "Missed" section so I'd have replaced that with Control Centre. I'd then replace the swipe up gesture to bring in you in to multi tasking. To me, a swipe up to access open apps, and as a means to get back to the home screen, would be much more fluid than a double tap of the home button. You would, of course, be able to disable this just like you can disable control centre in apps. I honestly don't think a swipe down and then a swipe left ("Missed" tab) to reach controls would be much of an issue.
Secondly, I like how the Maps UI auto brings in a darker look at night/low brightness. I think that applied throughout the OS would be pretty nice, if optional. The Digg app does this now, it detects your current lighting and time of day and then will automatically use the dark theme. Given how much of the UI uses white, I think this would work pretty well.
Edit: Actually, I really hate their decision to put those little grabber/tab things on the Notification banners. I know they can pulled down, I don't need that ugly little bar on each one to tell me.