I'd venture to say he's definitely more on the hero side of things, but also he's gained a nuance to his morality (less how he acts than how it's presented, perhaps) that squeaky-Clean Captain Marvel and his edgier replacement Shazam are just not that good at.
Ironically, I think the golden age Captain Marvel Jr, with his relentless drive to kill Nazis and lots of them, might potentially make a better foil to the similarly ruthless but well-intentioned Black Adam. Just a stray thought!