Debatable really. I had cod6 for a few months before I got black ops, and tbh what I found was that the game is amazing for 2 groups of people:
The pro gamers... There's quick scoping and drop shoting, which is what they want, as well as nukes for them to try and get.
And for people who play in groups. 6 man riot shielding Is sooooooo fun! So is random noob tubes, rushing, everyone walking around doing 360 C4 kills. Yea it's really good game for doing the above, but if you don't have lots of friends playing mw2 then I wouldn't recommend it over black ops. Still an awesome game though!!!