I just got insta killed by an AT mine while on the top gunner. I mean, nevermind that I have an entire tank to shield me from threats that come from the ground. Basically any explosive that sneezes on a tank usually is an insta kill to the top gunner, which is somewhat understandable if we're talking about a direct hit from a rocket, but from my experience, it happens all the time, even from land mines, which don't really make that much sense. They're so exposed, they usually get sniped long before they can spot and kill anything, if not insta killed by a mine. I barelly ever see anyone using it, and if I spot them on the other team it usually means an easy kill that can't be revived. So in conclusion, top gunners are useless.