I have one. He's been around for over 4 years now. I started with 6 but he killed all his buddies along with the 4 platties and 1 molly I had in the tank with him. I put him in with Bala's and a convict cichlid, thinking they'd show him, but now he just pretends to bully them around. Of course he doesn't get very far because theyare all huge and he is only about 2 inches.
IME they are Big bullies and will kill smaller fish than them. Well at least mine will. And he is not shy at all.....far from it!