It’s not unknown that ATI’s Linux drivers have been lacking, but they are constantly becoming better. Despite that, there are, understandably, those out there who complain on internet forums about their poor experiences. The reassuring fact is though, ATI/AMD is actively developing new drivers, and seems to have a tighter gameplan than even NVIDIA.
Each release consists of pure development time for roughly one month, creating a branch for that specific release, and then carrying out quality assurance. After development has ended there is three weeks of validation, three weeks of beta testing, and then one week to bake.
If you want to know more, and trust me, there is a lot of info here, head on over to Phoronix.
Source: Phoronix