Disclaimer: This is for the way above average geared HotA barbs.
Ive been discussing different builds and gear setup in a pretty informative thread in the US forums.
In my findings, berserker rage proc's more often then brawler for a HotA barb. (verdict is still ouf for ww/nado build)
I know there have been faster kills, but iam happy with my times. Especially since iam able to play at mp10 with that gear without dying.. (cant farm with the gear combo that currently holds the record)
In my "sustained" testing i found that rend aint worth the hassle of losing fury. So i used warcry with +fury rune instead, for a shortcut to +25% damage from berserker rage.