Yes - I've seen that around as well. Tempted to give it a go. One thing I did find is that Amazon wasn't the cheapest for the ONR - I got mine from motorgeek.
Going back to the pre spray, I noticed that the first pass might have been a bit gritty but then, as if by magic, the grittiness disappeared and it was really slick. There are some really dedicated users of these products - serious detailers - and scratching does not seem to be an issue.
Now I'm a believer!