Even if "a lot" of Beria's perversity was made up, there's still so darn much of it that it paints a bad picture.
Well, it's not mattering much unless his opposants have political levy and all.
Mao was... disgusting, by example. NEVER washed his teeth apparently, and liked... YOUNG girls. Or so it was said.
That was scary as hell.
I remember from some book that Stalin didn't want that his daughter spends even a minute with him in the same room.