I am getting used to the multiplayer. Early on I was dying too often and then rushing out to die, so I had less than a 1:1 k/d ratio. The last few nights I've played (20 matches or so), My k/d ratio has been like 3:1 and I was the top player in several games. Part of it is better equipment (I pretty much suck with iron sights), but even though I got the game a mere 3 days after it came out, peeps had already learned the maps and spawn points.
Finished the campaign and I didn't really care for it. There was more gameplay variety, but this was by far the most linear COD and the story was shite. At least they kept it short.