I did it in about 1 1/2 hours using HERO / Henches, never died, and had only one henchman death from a trap. I don't have my skill lists but here are the basics. Got 2 diamonds in the end.
Myself as a Paragon/ Warrior, TNTF, Save Yourselves, Focused Anger.
Paragon 1, Motivational Healer.
Paragon 2, Command, and conditions caller.
Necro /Paragon. MM Orders, with Motivation healing.
Hench Healer
Hench Protector
Hench Interupter
Hench Barrage
With GFTE going off every second or so I was able to keep damage up and constant. Livia made great use of the Wham-Norns. As soon as they died I made bone fiends. There are plenty of bodies in the area so make good use of em.
Just from personal observation I'd say Frostmaw alone was worth the purchase of GWEN. I was in constant battle for almost the entire time and it felt very epic with the Norns helping. I found it challenging and exciting at the same time. I had no idea Frostmaw was 5 levels down until I beat it. It had a distinct Aliens vs. Predator 2 feel to the entire mission. Especially in the bottom area with the giant caves, and crystals all around. I felt very deep within the depths of Tyria, and it was everything a good Dungeon should be.
When the Frostmaw Spawns appeared along the way with groups of other worms I could almost reach out and feel the breath of death from their jaws.
Frostmaw was truly epic.
