I would like to bring my experience with the latest version of Catalyst drivers (currently 11.8) on a fresh install of Fedora 15 on my laptop.
I have to say the open source drivers seem to work without problems (I installed and updated the OS a few hours ago.)
Using the ATI drivere the task panel of Gnome 3 is distorted, plus the movement of the windows is slightly less smooth than with the drivers provided with the OS installation.
Apparently this is a known bug.
In addition there is a strange problem with the dual display configuration.
The "Multiple Desktop" option in Ati Catalyst Control Center does not work: logging out and in again screens only show the background.
But if I use extended desktop, the behaviour seems correct after a log out / in.
On reboot, however, whatever the setting, the two monitors show a low-resolution cloned desktop: the same behavior you would get if, booting the laptop with the external display unplugged, you plug the HDMI cable during the session.
Have you had similar experiences?