Earlier quoted context omitted.
The community drivers are pretty limited if you need to drive more than two monitors or need to work with non-trivial OpenGL applications or games. Neither open source driver has very good power management, either. They both leave a lot to desire.
For what I see, future is bright on AMD side for those features. I don't follow the news closely, but phoronix reports on the subject have change from a long string of steady bad support and performance to a seemingly constant progress since last year.
The big change is definitely dynamic power management in the OSS drivers - now my PC doesn't sound like a turbine while I'm in Linux all the time.