Here's an interesting side-effect of the COD4 map pack: ever since I downloaded the map pack my K/D-ratio started to suffer terribly. Once I deleted the map pack from my HD the ratio immediately improved. Looks like the map-pack was mainly purchased by hardcore players, so that there are not enough noob players like me available for fair match-making. So the DLC actually made the game less enjoyable for me. Well, I didn't like Chinatown anyway ;)