The damage is enough of a reward. I'm not a big fan of stuns period (excluding Dbash). I can't see anything that takes control away from a player in an arena shooter as good design
The thing is though, it's only tier 3+ weapons that have stun to their power attacks, meaning that axes, clubs and mauls are the only weapons that stuns with power attacks (excluding power fists and klaws, because I SERIOUSLY doubt anyone can survive 'dat!)
