I've used it. It can be sprayed, brushed or rolled on, depending on your application. It says to put 2 coats on. Everywhere that I put on two coats looks great after three years. I have serveral spots that only got one coat and some of those spots have rust bleeding through. I haven't used Por 15, but if they were comparable, dollar for dollar, I would probably try the POR 15 next time.