The chopper gunner can be pretty unbalanced in the right cirumstance. I see it easily being banned in clan wars. While trying to get hardline pro in TDM on nuketown I got the chopper gunner. I was on 10-15 kills and ended on 36 after it left. Fucking rediculous as I could see the enemies spawn and I was just chopping them. I'm going to upload the vid as its pretty funny.
I apologise for the 5 second freeze in the vid. This was me pressing start and trying to figure out of you could show the score by pressing select. Guess not
http://www.youtube.com/watch?v=OiASP73-rYY