How Unity, Compiz, GNOME Shell & KWin Affect Performance
Interestingly, when running the Qfusion-powered Warsow game, the Unity test run's frame-rate had decreased dramatically under the AMD blob and was no longer running close to the GNOME2 / KDE speeds. GNOME Shell continued to perform most poorly with the Catalyst driver.
With NVIDIA, it was the same story of KDE doing the best but between the rest of the configurations, the frame-rates were close. The open-source drivers were not too interesting with their current Compiz issues.