As of now (Mac version 6.1.0), HL2DM runs well enough that I can play enjoyably. There is sometimes lag between my mouse movement and the game's response, but it is small enough that it doesn't hinder my play much. It's possible that people with less powerful computers may have a harder time of it, however. Generally, HL2DM in Crossover does not play as smoothly as UT2k4 (the only program I have that I can compare it to), which I play natively in OS X.