it's a sealer type product mostly. nothing !!! kills rust unless you blast it down to the metal then seal it from moisture.
there are several products on the market that pretty much do the same, or at least tought the same outcome.
i have completely painted (by hand) my whole frame in gloss black, front end in dull black, and inner fenders gloss, many dozens of small bits on Caroline's Lucinda Bolt w/ this stuff. if it lasts me 15-20 years I'll feel good cause I'll be 70 by then. Lucinda's a daily driver.

spraying this stuff can be VERY hazardous

The main thing about POR15 is avoid direct sunlight from it so under carriage parts are what you paint. :p
so
there are many ways to look at the answers. do what you believe is the best for what you can do. it doesn't make much sense to me to buy and ship paint from a catalogue when you can buy something locally that is just as good.
hummmmmm