As an AST I can tell you that the only time you should be DPSing is when 1. Tank is geared and knows how to use cooldowns. 2. The tank is only pulling 1 group at a time and not pulling 2 and 3. 3. With the amount of big D hits mobs are making and the amount of MP they are having to use to spike heal DPS who cant stay out of AoE's, Waisting your MP on DPS is not worth it. Our DPS is garbage anyways... at least as an AST I havent played with SCH or WHM but I dont imagine its any better.