Well, an "in the zone" sniper killed like half of the aliens of a terror mission in a single turn, allowing me to save a lot people. Also the medpacks of a doctor skilled support are so helpful in long missions that I usually bring two of them. I think it's pretty balanced.
I had to assault a large UFO once with one assault, one heavy, two supports and two snipers due to casualties from previous missions. The result is that I'm camped out in a doorway trying to fend off about ten aliens, all chrysalids or floaters, with a squad made from "I can only use my pistol!" and "All I have is this shitty assault rifle." Didn't go too well.
My assault guy, on the other hand? If he doesn't kill a chrysalid with the crit from his second shot, he's guaranteed a finisher on the free shot when the enemy closes within three tiles. Heavy with shoot, overwatch, second reaction shot after successful first is also useful as fuck.
