Side note: IW and MW3 have released multiple statements essentially saying that the kill cam is NOT "accurate." It is simply there so you can see the location/way that you died. So don't get too caught up in the "I shot him 4000 times and the camera didn't even show it." I learned this the hard way, but it relieves a lot of frustration when you accept it!!
IMHO, I would run concussion grenades over emp or flash bang. If anyone is looking to learn the ropes, or just needs a group you can always shoot me an invite/message!