The first test up was Nexuiz where the Catalyst Linux driver continues to be significantly faster than the open-source drivers. Fortunately, with Linux 3.7 + Mesa 9.1-devel there are significant performance improvements for this formerly popular open-source game over Linux 3.5 + Mesa 9.0. With this very latest Git code, Nexuiz on the Radeon Gallium3D driver is finally running at more than 50% the speed of Catalyst on this modern Radeon graphics hardware.
There were some minor performance improvements out of the very latest open-source Radeon code with OpenArena 0.8.5, but the Catalyst driver remains significantly faster.
OpenArena 0.8.8 isn't much of a different story compared to the older OpenArena release that is more lax with its OpenGL usage: the open-source Radeon driver is still much slower than Catalyst but there are some modest improvements to be found out of the latest developmental Radeon Linux code.