Agreed, my first brew after crushing my own grain was 80% with the BC, and I was super happy with it!
Ironically enough, I had my first probelm with it last brew day, the secondary roller was binding, and I have no Idea why, I had to remove the set screws and tinker with it to free up, I assume some grain got bound up between the roller and the "box", regardless after reassembly it was all better.
Don't listen to the Monster Millers, and Crankendsteiners that think their mills are superior, they are only more expensive! the BC is awesome!
Like you said factory setting are great, but I was thinking of tightening it up slightly for a little more flour in my mix, I think it will increase my efficiency a couple points maybe up to 82-85%, and that is about as high as I would wanna go.
Anyhow +1 to the BC and it's value!
Cheers!