I know everyone is going to say shoot a fixed blade - I have gutted myself with the same question many times for my elk hunts, once even using a Montec. For my hunt last year in Montana, I decided to shoot a Rage Hypo. I was nervous thinking the guides would be upset with my choice. It was a tremendous relief when they all agreed that the best broadhead for elk was a Rage Hypo and that is exactly what they all shoot. They all agreed, that if you shoot one "in the shoulder", it doesn't matter what you shoot it with. If you make a good shot with a rage, it would splice him open and leave lots of blood.
Just my $.02 for what it's worth. Oh yeah, I am going back this year and will be shooting a rage again.