Stunning, awesome figures, but off like every stormtrooper figure ever.
As far as I recall, no differences for armours beyond the way different pieces may have been trimmed or fitted on individual suits, you can see variations in the films but there was no 'stunt' or 'hero' per se.
I'm actually wondering if the weathering can be removed from the upcoming Hot Toys sandtrooper. The raised brow and extended frown in prototype shots looks closer to the stunt version than their Hero version looks to its screen used counterpart...although proportions on the tubes are still off.
I actually measured the Marmit and Hot Toys helmets with a digital Vernier gauge...they're so close it's ridiculous, but the Marmit is still a touch closer to the real thing.
There are three primary issues on Hot Toys (this is psychotic nitpicking, guys...these are still great figures) .... the lateral tubes are too bulky, the divot on either side of the nasal bridge isn't quite pronounced enough, ridges around eye lenses too soft, and the "face plate" (area between the eyes and "mouth") could be a touch wider; it's also narrowed by the bulk of those tubes.