Everyone keeps saying go frost and sure, if its level 80 guys I do. But right now I am farming DM for my Insane achievement and frost just goes to slow. Especially agents the bosses.

Now I tried a frost fire build, and takes the bosses down fast, but doesn't have alot of aoe or protection on hordes of even 60 mobs. Is there a hybrid spec out there people use? I am thinking of twinking my own that is a hybrid frost/fire.