The last time I played HERO was fourth edition, and almost exclusively as a superhero game. (I played a lot of Champions in college before that.)
I've made a few characters in 4th, although I haven't tinkered with the system except (IIRC) to improvise power advantages and limitations.
That said, HERO isn't my favorite system. Superheroes aren't my favorite genre, and characters that I've seen for other genres look like low-powered themed superheroes to me.
"On two occasions I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question."
- Charles Babbage (1791 - 1871)