This is a portion of the PM I sent to the devs in regards to blaster defiance.
I tried my level 29 Energy/Energy blaster, street hunting in Independence Port and Talos Island. I like the Defiance power. It's pretty nice, but it's a bit buggy. I think that it should increase in direct proportion to the decrease in hit points. The way it works right now it's kind of pointless, since when you get to the point where it can really boost the power of your attacks, you're pretty much going to die from a strong wind before you can get any shots off anyway. If Defiance increased steadily as hit points decreased in direct proportion, it would be a LOT more effective. As it stands right now, you don't even have a 20% defiance boost with an amount of hit points that a green conned minion can one-shot you. It looks like you need to have less than 5% of your hit points left to get the maximum Defiance boost, and blasters never survive when they're down to that little amount of HP. They won't live long enough to fire one last salvo. If you've got a defender in your group always healing you, then the power is kind of pointless since you'll never have a low enough HP balance to increase Defiance substantially.