multi: its awsome now you can spitscreen online :) you can see people easier not as much recoil in the guns either. i dont like the sounds of the gun the gunfire didn't seen as real as mw2 did. ( i own a couple myself so i know)
campagn: havent gotten too far but the story has really caught me the gameplay is just like mw2 witch is good i didn't thing they need to improve much there.
Game has good campaign mode and online play is better than MW2. Less lag and kill streaks aren't so devastating that people will cheat to get them...i.e hiding in rocks, floating in the air. quick scope is gone as well. Graphics are a lil sub par to MW2 though.
Call of Duty Black Ops is just freaking amazing. The balance feels so good. The graphics to me is just amazing. Out of all the COD games this is the best no joke. If you look back at all the early COD games you will be amazed on how far COD has come. The guns are well balanced and the single player is ultimate in COD single player.