I'm running Fedora 17 (kernel.86_64 3.3.4-5.fc17) on my HP dv6z-6b00 CTO (A8-3530MX and Radeon HD 6750M).
A couple months ago I was running Catalyst 12.4 without too many problems, although it lacks several features (e.g., crossfire and dynamic graphics switching) available with Windows 7. Since then I updated to Catalyst 12.6 beta (which displayed a testing use only watermark) to the final Catalyst 12.6. Strangely, now I have an unsupported hardware watermark that I never had with Catalyst 12.4. Things with Catalyst 12.6 seem to work more or less similar to Catalyst 12.4, but the watermark is annoying and indicates to me a step backwards in support. What happened?
I'm also interested in other customers' experiences. What other things seem to have improved/broken or not changed that you were hoping would?