Funny you should ask the same question I asked them. "Why are folks using this instead of Nuvite? What advantages?"
They said their product did just as fine a job with a whole lot less expense.
They also sell a product called "Agent 99" for aluminum skin that is in need of a more aggressive approach. I figure if the stuff is good enough to restore a 1958
Beech Model 18 ($175,000.00) is good enough for my Airstream.
So far...I'm very pleased, and at around $65.00 a gallon, it is certainly cheaper than Nuvite.