My guild is currently running Naxx, and I'm 1 of the slower levelling tanks. Just hit 80 over the weekend and got all the upgrades I need from normal instances. I got a rude shock doing H-Azjol Nerub and H-Gundrak, when I was taking up to 11k hits.
I badly want to start Naxx, but now I'm not sure if I make the grade considering how awful it was tanking heroics. This is my armory below: