Yeah. It’s not my guide.
It’s written by Rage, who, along with Justin, literally broke down every minute mechanical detail of the build, found all the bugs, and pushed it to its limits.
So, when you’re talking about “pros,” you’re talking about this Barb forum.
I’m not trying to hate on IV – of late, their guides are much improved, and they have some fantastic content, but I maintain that the Barb forum here is the best repository of class knowledge, especially for builds and class mechanics.