farming those as well. Although my wizards do that so much better. and they kill the ubers in like 10-15 seconds (except diablo that can be a bitch sometimes).
anyway, if you take CotA TaO you lose the fury from the other rune, not sure you can afford that.
I think I'll try something else instead of rampage, even if RG spawns adds, they die so fast and give you 3-5 stacks, and these stacks usually fall off before the next batch of adds comes.