(Edited the title to better suit the post)
Im thinking of moving from Windows since my ATI card got crap support on Windows 7 and Vista's getting slow.
My only linux experience has been with Ubuntu but i really like how fast and responsive Sabayon 5.0 x64 is with Gnome.
What im conserned about is how the Open Source ATI driver will preform with games like WoW and CS 1.6.
My graphic card is a ATI Mobility Radeon X1600.
Anyone got a similar speced ATI system who got any experience with gaming under the Open Source driver?