stack power. The best mods are in the enforcer bracers, and enhancement is in the field medic boots. Depending on your play style people use a different amount of crit, mine right now is like 37 something%. Once your surge gets roughly 75% I would start thinking about switching to the enhancements with alacrity to get cast times a little lower. There is a WH enhancement with low end high power and high alacrity which is nice because they are really cheap to get. Don't go too crazy min/maxing because 2.0 is already on the PTS and will have new gear and the stat priority will change.