Well the title of the thread is "paint or por 15?", which sounds like a debate to me. I simply shared my experience, and made my recommendation accordingly. I still recommend Eastwood's Ceramic Chassis paint, it holds up better and looks nicer than por-15 from what I've experienced.
Everyone agrees that por-15 sticks better to rust. Your frame has been blasted and primed, so what will it stick to? Painting a rusty frame with por-15 is a cheap repair. You on the otherhand have already started down the road for doing it the proper way with blasting and epoxy, so why take a step backwards with the product you put on top of it? If you've already done it, then keep tabs of how it holds up, I'd be curious to see if you have better results than I have in the past. If you still are on the fence about what to use, I'd use the paint I recommended.
If you want to try for the ultimate durability, why not get it powder coated?