For pure burst, you're probably looking at 0/20/0. But not getting hawkeye is retarded. So...for BG play, 0/17/3.
I actually spec'ed for defensive play, as I consider it more fun. I'm currently 0/9/11. As long as there's another healing debuff on the team, we don't really lose much. However, I'm able to protect dumb healers much better with scatter shot than I am watching them stand still with a frost trap on the ground.