Has a lot to offer, but poorly delivered
It's hard for me to be more disappointed. Now, I will not fault the storyline, because if there's on thing IW does, it's come up with a good story. It's the fact that the game scales VERY poorly on mid-range computers, among other things.
I run an ATI HD4650, 2 gigs of ram and a dual core 1.8 gig processor, so conceivably it should run this game at medium-high settings with stable frames. What I discovered is that this isn't actually a PC game, it's a console port. I learned this from the moment I started playing because I COULD NOT LEAN. I immediately started having FEAR 2 flashbacks, except I wasn't planning to be scared, which FEAR is intended to do. I was planning to have an action packed, urban shoot out. I got that, except I couldn't look around corners. For CoD on PC, this is a must have, and I believe it lends significantly to the difficulty of the campaign.
As for the frame rates, there's no console (~), as this is a console port, so there's no way to check your frames. I put all the settings to their very minimum, and still got serious drops when looking over large areas or at bright flares/fires. This is due, I believe, to the inability to change the amount of detail and number of world items. Therefore, more console-ized bullcrap.
On a side note, the nightvision looks TERRIBLE. I'm not really sure what they were thinking, but it looks very washed out and white, instead of a dark green. It actually made it harder for me to pick out details in the dark than when it was off. Which leads me to my next point, the blood splatter. I know a lot of people think it's great, and I myself thought it was a nice touch at first. But that was before I started all my missions surrounded with minimal cover, constantly being wounded and unable to see a single thing except for red. So, in hindsight, I think they should have chucked the "realism" thing for better playability.
I have NOT played the multiplayer, but I'm not as excited as I used to be. A lack of dedicated servers and only 9v9 really takes away any of the reason I played the first MW online in the first place. Playing games of 15v15 with no noob tube or martyrdom is much more fun. Also, I've heard (and seen, if singleplayer is any indication) that it's a spray fest, as pretty much no automatic weapon has any sort of recoil at all, so one can sprint around blasting and get insane kill streaks (which I also hear can be pretty game breaking in themselves).
All in all I had to be generous and give it a 7.5, just because if my rig was better I could run it smoother, and the story was in fact very enjoyable. But for $60 (Jesus....) and what I was presented with...I'm just disappointed.