well I didn't buy the game either but I just completed single player :P
took 6 h 9 minutes according to the game itself...
The amount of weapons in this game boggles me.. really I don't think i've seen the same weapon more than a few times...
spoiler below
Personally I liked single player alot.. Maybe down the road Ill buy the actual game but i'm still kinda weary about the multiplayer experience... i think that youtube video going around doesn't reflect everyones gameplay but it definatly highlights a big issue..
Also my biggest issue is that with the current nvidia drivers 191.07 the game does NOT run in SLI.
I have a EVGA 295 gtx card overclocked to 704 on the core, 1536 on the shaders and 1207 on the memory with a i7-950 on stock (for now :P) and I'm able to run the game with full settings at 1920X1080 resolution with a few stutters (I didn't play the game with frame rate showing the first time around, might play it again). For those of you who don't know the 295 is basically two 275 GFX cards into one that consumes less power.
I'm not particularly interested in running beta drivers and I heard that this fixes SLI in MW2.
I'm also assuming that the game WILL have a fix for SLI down the road (most likely via nvidia with a driver update) because both cod4 + cod5 have sli.
For now it gets an 7.5/10 on my part. SLI fix 8.5/10
I would have given it a 9 / 10 but there are WAY too many ammo depots in the game...
spoiler.
Edit: just so you know this is based off of single player... not multi