None of it matters. It's all a gear check. I have an amazing lineup, but not enough dps. I've now been grinding gold and gear for 2 days straight. Trash rolls on gear. I'm @ -18 on all 3, and I'm stuck like chuck.
I didn't use the end-game set bonus, but my Styx/Wisdom/Glacier sets on Atrox/Greed/Dolores were strong. And of course, there is some timing involved, but that was it.