My lord guys, there's no difference between MW3 and Black Ops 2..you're just hating it because you don't have it or because it's not "the newest"
You might want to get:
QuickDraw
Deadsilence
Sleight of hand
Then a gun you should get is the L188A or the MSR because it makes it A LOT easier to quickscope.
When you dont use quickdraw, you want to blackscope more, and for the newcomers, a black scope is basicly a quickscope, but you dont see inside your scope, it looks like a glare. If you have your Crosshairs on the enemy, (In the middle) and look down your sight untill you see your scope, then shoot, back out of your scope at the same time, It will hit.