So, here is my list of bug and unwanted behaviours
4) Don't put a picture with a light background in the lock screen. It just disables you from seeing the controls
6) Now in the latest Beta 5 you'll see all the birthdays one day earlier than they really are. My contacts APP is telling me that my birthday is the 18. of September, but in the Calendar I see it on the right date. So by restoring it for displaying in the contacts they'll make some kind of mistake
I'll put more of those as soon as I find them.
All in all I like the new look and feel of the OS and even the new functions are nice, however there is still a lot of work for Apple until they can distribute it to the market.