Just a few issues but otherwise the application runs very smoothly. Only 1024x768 and 800x600 are listed as useable resolutions but I didn't try editing the UT2004.ini to go higher. Changing resolutions from within the game often results in a fatal UT engine error.
All settings are turned on, pixel shaders and vertex shaders running in hardware. Driver emulation checkbox in winecfg > Audio is a must for good sound.
TURN OFF THE PROJECTORS OPTION otherwise the video will look torn and combed whenever a player or vehicle enters the field of view.
If I try the Mactel version of the game I will relate performance differences.
UT2004 Version: 3369
CrossOver Version: Mac 6.0.0