Playing TF2 via cxgames, I get very low fps. I use a 7900GS, for comparison on windows I can get around 40 or so FPS on max details @ 1440x900.
However, using crossover, I get 10 fps or so, which as you can tell is a big setback, using dx8 mode gets me maybe 20 or 30. Is this just because DX9 support isn't amazing in wine at the moment? Everything works well though, and I don't mind playing it in DX8 too much.