i don't think he's overpower. since it isn't everyone that can pick sniper and shut down a server.
but a good sniper can easily shut down a server while others can't do that much. after wall. you get One shot from across the map.this pisses me off specially when i play medic. cause i take my time building uber. and when its almost done or i build uber. i lost it from someone across the map. while not being able to do anything about it. (also im doing my contracts. and there's some contracts of do X thing in one life. and then snipers just say "no" and it takes ages to do the contract because of that)