I think this simple idea can bring a lot to your visual experience, it wont give you back better textures and destructible environnements but to me only this is night and day . My normal FPS is 60 and I was kinda disapointed with the graphics out of the box, however forcing the max fps to 30 give a really great REALISTIC edge to the graphics and do not hinder gameplay at all. Here's a video I uploaded keep in mind this a 200 mb video compressed from a 3GB one so in-game is even better IMO. Try it for yourself, put this into your autoexec.cfg file: sys_MaxFPS= 30
http://www.youtube.com/watch?v=6GGkkEDeUvw
P.S. the other videos on my youtube page are based on the same tweak