I quite like it (PC, single player mainly).
The graphics match BF3, it didnt have anywhere near as many silly, press this button now, now this one etc moments, the guns feel better and your aim doesnt wobble all over the place, it doesnt have as many stupidly hard sections as on BF3, the spec ops bit is bloody good (and hard!) and the online spec ops is even better. Add in the fact that its missing the whole stupid story thing that Blops went with and BF3 copied and I really like it.
Havent tried it in the normal online modes yet but I CBA with that sort of thing anymore, F1 and Forza are more my kind of online play nowadays. Saying that, I never really got BF's massive map online play, it always bored me senseless, I much prefer to pick a game up and blow away an hour or so and BF never really suited that approach to gaming.
The only problem with it is that there is no leaning anymore (thanks Xbox/PS3) which I miss sooooooo much.