One of the problems is playing Call of Duty on a console. The PC version is much better, more players, more fun, controls are always better on the PC for FPS.
That is the main mistake you made, buying an FPS that was built for PC gaming on the console. And really I don't see the lag problems on PC, the maps I think are way better, it's a lot more smooth, not a super fast paced P90 crap shoot, and gore, LOTS more gore which is awesome.
Sure they could of done away with some of the stupid stuff like Marty and Noob Toobs, but no game is perfect. I perfer this over CoD 4, and to me the graphics are a bit better, the sound is way better, and the gameplay is better to me.