I've been boosting with my 84 dk. Hes at about 97k hps, not sure about armor. Hes not as fast as other boosters, but hes the best i have. Low level up to mid 60's hes pulling from boss to boss in instances no problem. By the time i hit wrath instances i'm pulling 2-3 packs at a time. Hes in blood for spec and presence atm, but up to 60ish I ran him blood spec and unholy presence for the speed and dps boost. I've got 7 weeks or so left of wrath, considered leveling to 85 and getting him some gear to speed things up.