If you compare the tanks across the board DRK falls short when it comes to Defensive Buffs, Self Healing, and overall raid utility. I was of the same mind as you but then play warrior and you will feel the self healing doesn't even compare. War can heal for 10-12k+ on a pack of 5-6 whereas DRK is 5-6k.

If you like DRK I would stick with it. Changes are coming.