I have a Model A tudor body that was blasted and primed with epoxy primer in 1990. The body sat outside in the weather for several years. It now has rust stains coming from between the panels, where they bolt together. I really doubt that the etch primer would have held up that good. I have used the etch primer that Nason has. The stuff that I used was not as protective from the moisture, and I have actually had to completely sand to the bare metal to remove hand prints from it. That is enough to convince me. I have also used Nason BC/CC and gotten good results from that. I would however make sure that the proper prepwork is done, including using a quality epoxy primer.
"i have no affiliation but have painted 2 cars using their products and they turn'd out fantastic...."
I have seen cars painted by Earl Scheib shops that looked fantastic when first done. Then a short time later the paint was peeling off. Sorry, but someone painting 2 cars really doesn't tell me much about a product. There are guys here that have probably painted that many in a day.