My opinion is that they're mostly hype. They all say "9H" harness, but does anyone know what that actually means? Or is there any accepted test to determine a paint coating hardness? Is hardness even a good characteristic for a paint protection?

I did a decent amount of reading and research and came to the conclusion that none of the fancy coatings will last more than a year or 2 tops. A decent wax applied 2x per year is probably better for 1/10 the cost.