I can tell you that this is a pretty gnarly loop. I was talking to the owner of Dirty Harry's think halters of Pittsburgh about this ride. The dirtier dozen certainly is a great ride if you are looking to be fairly miserable. But the guys that live in Western PA say that they are used to @ least 100 ft of vertical per mile on a normal ride.
wow, this really makes me feel like my great ride on the road today wasnt so great after all. those climbs looks ridiclous, especially the one on those cobblestones. But i really like the part at 3:03, Lefty FTW!