Ran my first dungeon as a DRK today. Had both Darkside/Grit up, but dropped Grit to pop Blood Weapon since my MP was getting low. One of the DPS saw it and berated me for getting out of tank stance to use Blood Weapon (admittedly, my word choice could have made matters worse).

End question is this - should I have kept Grit up the whole time and just used Syphon Strike to recover MP? Or is dropping it fine to recover MP with Blood Weapon? Or does it, like stance dancing in general, just depend on the healer?