I think you are making a lot of assumptions and drawing conclusions based on speculation ("it must have been soft paint" and "For this abrasive to be able to finish out nice on most paints, it has to be very fine and offer little cut").If he did, then it was on very soft paint, and any finishing polish would have done the same exact thing on that paint.
The premise of System One is that it uses a NON diminishing abrasive. For this abrasive to be able to finish out nice on most paints, it has to be very fine and offer little cut, other wise (since it doesn't break down) you would get a lot of hazing, hologramming, etc...
So any "cutting" it does is a function of the pad, not the polish (which is like 106ff already broken down), since the polish cannot have much cut and finish nice (because the abrasives don't break down).
Again, I ask, what is the difference between this fine polish and any other fine polish that uses the pad for cut?
Why can't it do what it claims to do? Why not try the polish and see for yourself? Or better yet, attend detail fest and prove the guy wrong in front of a crowd?
You said "any finishing polish would have done the same exact thing on that paint." Why not bring your favorite finishing polish to Detail Fest and remove 500 grit scratches with it in front of everyone to prove that SYSTEM ONE is just like any other polish?
Seems like there are a lot of people on this board (and others) saying that it works well. The only ones that are saying that it doesn't work well are people that haven't tried it.
Toto has wetsanded factory finishes (hard) and had no problems. Granted he didn't use 500 grit, but still, it wasn't soft paint and it worked.
I can understand being skeptical about a product, but to say it doesn't work without trying it doesn't seem fair, especially when there are reputable people saying that it does.