Here is some early WT4 nightmare dungeon gameplay of upheaval. I really enjoy the button mashing non-shout brawler style gameplay of barb. This is in no way a super endgame video and I have no idea how the build will perform at nightmare 100, but sorc's are clearing those dungeons so it's gotta be viable. Build info (gear, skill points, paragon) at the end of video.
Side note: I started with walking arsenal, but unbridled rage boosted my upheaval damage so much it just didn't make sense to stay with W/A. Maybe with high rage cap and kick maxed out with power kick augment Walkling Arsenal would be worth since it's nice to have two buttons vs one that does damage, but I'm just entering WT4 a