DRK for me has been a job of what not to do. I've worked most of the kinks out on OOMing but I still have trouble on things that take foresight, like boss jumps(shouldn't be a problem with experience) and unexpected aggro.

Drk overall is very fluid, but feels clunky when I have to wait for GCD to reset to take Grit down and put Blood Weapon up. If anything they should change "Cannot be used during Grit" to "Blood Weapon: Grit effect ends upon use."