When running OpenArena, which is less graphically intensive than Nexuiz, the Catalyst performance between Metacity and Compiz was now indifferent. The only change in performance on the proprietary Catalyst side with this ioquake3 game was the GNOME Shell frame-rate being cut by more than half.
Under the NVIDIA binary driver, KDE 4.6 was again the fastest desktop. The GNOME Shell + Mutter performance came in close to the same as the other desktops / compositing window managers.
With the R600 Gallium3D driver, GNOME 2.32 with Metacity was still the fastest while this time around for the Nouveau Gallium3D driver, KDE was the fastest.