Don't know how I missed it but I would alter your build slightly to get rid of overpower and replace it with HoTA smash rune. It works really well to take elite packs down really quick and then switch back to the WW spin for trash packs
The loss of the crit from OP is not that big of hit?
Depends on how much crit you already have. If you have 50% crit chance, I don't think you'll need the extra cc from OP.
But then again, this is high level talk, my barb can barely farm MP5.
Im playing a 190k~ dps ub barb (really ub, also no passives, comes down to 400k buffed dps constantly while playing) and Ive done some testing. I mostly just WW and use hota on elites. Mp 8 full runs, festering -> fields -> weeping hollow comes down to about 150 M/h. MP10 field runs where I mostly just kill whites, just on fields of misery + scavengers den/decaying crypt, I get slightly more, about 160 M/h. Im gonna test MP 9 and MP 10 full runs later.