I also have the occasionall hickup, but there aren't many of them, and the game only pauses for a split second. The "problem" is barely worth noting.
All in all, a solid, stable port. Thanks, Icculus! (I already had the game and was playing it trough in wine. I wasn't too far in it yet, so I can play the rest native. Biggest improvement is that I now have surround sound in the game, where as wine only supported stereo )
I didn't have the tiny hiccups in wine, on the other hand.