Please note this is an online multiplayer review only!
Firstly you can clearly see and feel that the game uses the waw engine but that's not a bad thing. Movements are slower, more laboured; you even get a grunt/groan as you climb over obstacles. No more superhuman running & climbing and thank god for the dive animation when going into prone while moving. Gone are the days when you start shooting someone running toward you only to have them prone mid sprint while shoot you in the toes! (You can't shoot while diving, and until you've landed your defenceless. Although diving does make for some awesome replays in theatre mode)
Another very welcome edition is the fact that guns seem to finally operate within their range and constraints. No more sniping with an acog'ed UMP or running with around firing a LMG without recoil. Quick-scoping also appears to have been toned down and could now only be described as scoping.
Many other elements that plagued MW2 have also been reportedly sorted, including boosters. Camping has also been cleverly reduced. Most areas have more than one access to them and those that don't can easily be cleared out with an RPG or well placed frag. Don't get me wrong there is still the opportunity to snipe but you just need to keep an eye out or use some special equipment.
Killstreaks have also been revamped, they're not too powerful and don't count towards other killsteaks. However I can see the RCXD or whatever it's called becoming a pain on occasions.
The currency system is a little odd. Although you can buy any modification as soon as you unlock the weapon, I think it removes the fun and variety of using different modifications. Would you of used the silencer/suppresser or acog in MW2 very often if you weren't trying to complete the challenges? But the COD points do offer one hell of a reward coming in the form of wager matches. The game modes are fantastic are reminiscent of the thing I used to do with friends in MW2 offline. It gives you the same rush you get from being the last man alive in search & destroy, mixed with the frantic action of a ground war and the fact that sitting in the corner like a baby will only make you lose your hard earned points.
The level of character and weapon customisation is also superb and surpasses any previous call of duty and possibly FPS. However it'll take you a while to fully appreciate it as many of the options are only unlockable at higher levels. Eg. Custom emblem on gun is lvl.16, the face paint is lvl.31 (I think.)
As for the graphics there nothing new, on par with MW2 but I defiantly wouldn't refer to them as terrible!
The maps are great, a good variety, mixing the best of MW2 with the best of WAW.
The theatre mode seems pretty comprehensive. I've yet to do much with it but I can certainly see it being a big hit.
To sum it up, if you're an IW fanboy, booster or quick-scoping obsessive you'll hate this. If you're more open minded, prepared to play fairly and sick of the problems that have crippled MW2 online (black ops seems to of sorted them, for now at least) then this is for you.
Is it the best online FPS ever? No, for me BC2 still holds that title. But it does a damn good job and will have you addicted in no time.
Is it worth 40 quid? Yes if you're playing online but I doubt it's worth it without.