I finally got around to playing this. I was kinda hard on the SP, because honestly...it feels to damned linear. Like, RE4 like linear. I could deal with both, but, COD4 just seems to be a bit more obvious with it than anything else I've played. Some of the shit done in this game is inexcusable. (I.E. all the locked doors and shit) Some of the set pieces were pretty sweet, and viewing through the eyes of a soon-to-be dead man, is pretty damned great. I wish more games did stuff like that. :/
The multiplayer is wtf awesome. I haven't gotten the chance to play it online, but, via splitscreen and the like. I've had a shit ton of fun playing against random folks.
Things that are awesome:
-No scope killing with the sniper rifle
-D. fucking Eagles
-Getting head shots through walls
-The effing shotguns.
I have yet to try out anything other than deathmatch, but, that shit has been a blast to play.
Oh, last stand with grenades is the stupidest shit ever. Annnddd getting multi-killed by a fucking helicopter sucks.