Warsow was broken on this Lenovo ThinkPad up until Ubuntu 10.04.2 on the open-source driver. The performance then was still shoddy due to classic Mesa, but with Ubuntu 10.10+ on Gallium3D, the performance is much better. However, the performance has regressed since Mesa 7.9 and even still with the latest Mesa 7.11-devel code there is a noticeable regression. However, what is interesting is that for this test it's performance is ahead of Catalyst -- this time by 67%.
With Warsow at 1400 x 1050, the latest ATI code is still faster than Catalyst and there does not seem to be a Mesa 7.10/7.11 regression at this resolution like there was at 800 x 600.
The results from testing each Ubuntu release to look at the open-source ATI experience are not surprising. The open-source ATI Linux support is a hell of a lot better than it was two years ago. There's now mature DRI2 and kernel mode-setting support, the Gallium3D drivers (both R300g and R600g) are now superior to the classic Mesa drivers, and many new features continue to be implemented that allow for better performance or in other cases for OpenGL applications/games to properly work. With the landing of KMS page-flipping and other recent work, the "out of the box" ATI experience in Ubuntu 11.04 should be quite pleasing and noticeably better than previous releases.