I'm on a MacBook Santa Rosa 2.2GHz: http://support.apple.com/specs/macbook/MacBook_Late_2007.html
I run OS X Leopard 10.5.5 and Nexuiz 2.4.2 glx has never given me problems.
Recently I've compiled Nexuiz from SVN trunk (and updated + recompiled it a few times) on os x, following this (outdated) topic: http://support.apple.com/specs/macbook/MacBook_Late_2007.html and finding my way into a working nexuiz.app
Nexuiz SDL works the same way as 2.4.2 SDL (some inverted keys and a strangely resized screen): that's why I've never used it.
Nexuiz GLX, however, makes my mouse lag: for a few seconds it works perfectly, then slows down and stops at random intervals, and the game is unplayable.
The console shows nothing wrong and every other aspect of the game is as it should (that means like nexuiz from SVN on my linux box, that shows no problems of this kind).
I must say: to make the unix executable work in an .app I replaced the file "nexuiz-osx-agl-bin" with my newly compiled version, thus leaving all the other files in the .app folder unchanged. It's the only way I know it.
Thanks in advance for any reply, and great work!