Game is amazing, I think we all expected it to be, especially after the first Modern Warfare. Played the first level or so in campaign before I went on Xbox Live. No negative feedback as of yet.
Right now I think I'm at level 17 or 18, been using the FAMAS assault rifle strictly (I know pretty lame, but I'm all about the semi-automatics). Trying to get the next few levels so the hardcore matches are available to me (been piggy backing off my buddies so far to get into those modes).
Got to agree with Venomous on the Bling perk, but the heart rate sensor is pretty bad ass although it seems to have a smaller range online.