Mesa 8.1-devel On Radeon Gallium3D
There are no real performance improvements to note on Mesa 8.1-devel at this point for Doom 3. At high resolutions, it does seem to regress slightly compared to a performance improvement made during the Mesa 8.0 cycle.
Nexuiz is one of the DarkPlaces games where the Mesa 8.1-devel performance is dramatically better. At 1920 x 1080, the frame-rate is up by an amazing 2.7x!
Xonotic also enjoys Mesa 8.1-devel Radeon Gallium3D with its frame-rate more than tripling on this current development code.