I'll be interested in what those who attended have to say. I've known of both for a long time and employed the Barnett Manuals in my shop in the 1990s. These days I hear more about United, especially in the framebuilding world I follow.

What I would be curious about is the basic approach and goal either has. Are they more shop focused, getting the work out right the first time and without lost time. Or are they more to do with the analytical process and how to figure things out. Which will have more students that plan on a shop job or moving up the shop service tree or have those who need to be able to deal with whatever is in front of them. One of my good friends who leads tours for ACA and a for profit company took the United course and thought very highly of it. The little that I have seen the Barnett stuff the more I suspect they are about the retail shop experience and it's needs.

I have more stories about this but this is all that pertains to the OP's questions. Andy