I have done Blood DKs with 1 priest and worked my way slowly through an isntance. I noticed when I was solo queueing for valor that frost DK in frost presence does some decent dps in full PvP gear no less. Strangely unholy presence is only 10k dps. Anyways at 13k+ I was thinking that 1 blood and 3 DKs would mow through an instance much faster than 4 blood (only 6-7k dps). However survival would take a dip. Anyone tried this?