Almost 65, leveling as blood. Havent come across another DK that I havent been able to kill even when a level higher(killing 64 unholy when I was 63).
I haven't played Frost or Unholy, but I have 0 downtime as blood. I hear frost has a little bit of downtime, but that was through the grapevine, who knows?
I'll be playing the DK as my main and am loving it thus far. Only complaint is other DKs that are specced Unholy. After I kill them they return as ghouls and still do pretty decent damage and have full health. Scary when I'm somewhat low from the initial fight.
Human Death Knight 'Ataractic' on Deathwing(not showing up on armory yet for some reason). I'll link my spec when I get home from work.