LOL, Not really 'tender' Super but Over or Under each has it's camp followers, Us and Them, Mine and Yours, This and That, and all their kids to boot... and they just went to bed sometime last week agreeing to a non committal truce that each is 'right' given a varied set of of undefined exceptions.
Fillers are 'plastic' epoxy isn't.
Fillers can absorb moisture epoxy doesn't.
Other primers are also moisture absorbent as well, relying on the top coat to seal them.
If your working in production or are just that fast with your projects that moisture over time isn't of concern I don't see a difference but if your like me and take a while between stripping and paint the epoxy offers some peace of mind as to whats going on with the metal I took forever to expose in the first place.
But that's coming from an avowed evangelical pagan...
