The thing with the burster is, it dominates air vehicles, faster then the other 2 AA maxes. It just doesnt have the same range.
If a reaver or something gets close enough to the ground, and you are locked down BOOM you are dead b4 you knew what happened.
I think is fair cause you can stand from a tower and take down infatry from 50 yards while the other aa maxes have trouble taking down one agile with a MA wep.
Plus, TR gets the kill all magic striker, who needs an aa max?