Steve, you and I agree 99% I just leave room for the talented 1% who can consistantly move down 0.1mm and hold it there who look at the rest of us wondering why we can't.
I can see no reason to run a compressor at 40-50psi and use the down control to reduce to 20-25psi for spraying. Even at that pressure small or flat parts blow away, at least they do for me.