http://wowwebstats.com/tgbml6tsc5sdk?s=bosses
Look for Cirrus. Global dps gets inflated by Thaddius and Loatheb (and bosses with some AoE component) and deflated on bosses like Noth/Sapphiron (dispell) or Maexxna (stun). 4.4k on Patchwerk isn't really good, i've done up to 4k9 with lower gear than i had there. (bad luck on Eclipse proc plus a solar proc at least :/)