Just been there wiping endlessly on the last boss. Group configuration of Prot Paladin, Arcane Mage, Destro Warlock, Disc Priest and elemental shaman. Simply couldn't keep up with the adds, ended up having to bring a healer friend. Problem was the add control. seemed when she enters on phase 2 I never have enough void zones to keep the adds occupied.

All my chars were lvl 84, using every possible way to kill the adds but its just too hectic. Specialy on phase 2 the swarm of adds just gets me. Have to revise a bit my tactics or the group config before getting another go at this.