If you claim iOS 7 lacks basic functionality, then (by virtue of the word 'upgrade' ) iOS 6 would've been lacking more basic functionality.
(Just like Windows XP lacks some functionality found in Windows 8.1)
Nonsense. Not everything is always better in a newer version of software.
As to the question, I'm torn. There's a lot I like about 7, but the calendar in notification center is now completely useless. I used to use that a lot, but not now. The dock on the iPad is fat and ugly. Folders are also incredibly ugly and they made the number of icons per page smaller, but at least they added pages to folders. But overall folders on the iPad continue to be disappointingly inefficient. Also, the new flat look sometimes makes things non-distinct. For example. When adding a photo to an email the menu bar at the top of the add photo window kind of gets lost in the white background of the email. They are nearly the same color with no distinct borders. And maybe I just can't find the option now, but is there a way to delete all email now? You used to just be able to mark all and then delete. But now I just see a flag all, but no delete all option.
Anyway, I got the new Air so I'm stuck with 7 now. Hopefully there will be a jail break to fix some of this stuff.