If you got the PC to run it, it's great. Don't be swayed otherwise. It's a solid game in the series.
I only played the MP. I maybe put an hour into the SP, but I find them kinda boring vs. playing real people. Black ops did get a lot of criticism early on, but Treyarch supported the game nicely. More than I can say for IW on MW2, who never addressed the hacking/glitching and problems with IWNET and screwed us PC players out of dedicated servers.
Black ops is better because it brings back dedicated servers, console commands and feels like a PC game again, but had MW2 had dedi's I would never have switched.
The maps are pretty good too. I have played 100s of hours and still love playing. Its better than MW3 at the time of this writing. Better late than never right?