Personally I never found them overpowerd. Your big hitters are mediocre by other standards, your shooting is just ok, your armor is just ok. They have a unique playstyle, similar to a tank class in other games. You might not kill a lot but sure as hell the enemy will struggle to kill you.
On one hand I agree. On the other hand, none of my other factions drop the line 'ok, that's six BTS rolls, damage 17' (or 16, or 18, depending on model) especially often. :P