After spending about 3 hours each in Campaign, Spec Ops, and Multi (got it from the eBay seller mentioned earlier in the thread):
Campaign is ace. Unfortunately I knew about certain events before playing, but other twists and turns are unexpected. It's standard CoD, but amped up. The spawning is MUCH improved, I don't know what the others are talking about. Sure, there's the same "move forward" philosophy, but if the "monster closet" design is still in place it is very well-hidden. Also, the "grenade rain" is gone. They still throw grenades, but they are fairly rare. So far, the days of seeing 4 indicators on screen at once are gone. This is all on Veteran, by the way.
Spec Ops is ace-er. We played through about 7 of the missions on Veteran. The variety of missions is really nice. Only problem is that Veteran gets hard QUICK. Already in the second stack of missions (out of five), we're running into brick walls. I didn't have too much trouble with MW1 or WaW on Veteran, so I know it's not solely my rusty skills to blame. Some of the 2-player-only missions are downright awesome (but again, so difficult).
Multi is great, but it has ups and downs. On the upside, the new maps/additions are great. There has to be close to 1000 unlockable items, from emblems to titles to attachments. On the downside, life is MUCH more fleeting than it was before. By the time you know you're being shot, you're pretty much dead. That's with the level-1 guns. I can't imagine how it works as you get further. It's still fun, but doesn't have the nice learning curve that MW1 had. Death Streaks help with this, but you kinda feel like Special Ed when you get them. I think that proper support will keep this one on the top of the XBL chart for a long time.
