I can do two an hour quite easily as long as I dont get:

Heroic PoS
Heroic HoL (lightning stairs boss man fucks me up, need help on this one!)
Heroic HoS (Brann Event is just a PITA. Doable but some wipes every now and then).

AN is my fastest and probably takes about 13 minutes. Crashin' Thrashin' Racer for the win. :P

I was wondering how you are resetting PoS trash for Hilt Farming? Does Reset All Instances work?