think the word you're looking for is immortal, unless you really do see "hulk fanboys" everywhere (and pretty soon "Reds under the beds" 🙂).
Hulk does rise from the dead though, so perhaps not conventionally immortal but still, functionally not very different.
anyway, back to Exiles Surfer. He seemed to have the same blummin' powers, rode around on a surfboard, fired blasts, used the Power Cosmic - explicitly made mention of it - and did pretty much normal Surfer things, aside from killing superheroes left right and center.
it's the ruthless martial mind and battle-ready, aggressive personality that really are the visible indications that Exiles SS is different from regular Surfer.
and because the PC can be used to amp and enhance Surfer's abilities to an unknown extent, and because Exiles looked like he was wearing some form of cosmic armour, I think it's fair to say that Exiles SS was somewhat more powerful than regular SS. also the size and potency of his regular blasts seemed greater.
I want to know why it would not be feasible for Surfer to just alter SMP's dna or cellular structure (by introducing a cancer for example) such that the solar energies can no longer be stored in them?