Every ship offers excellent potential for RP. Even my new piranha is fun. I even managed to scare a corsair praetorian out of New London with it. Guess it was so long since he'd seen one he was kinda puzzled. I also like the prison liner - the feel that it is a large ship with crew and different sections devoted to separate purposes.
I reckon the problem comes when people acquire them for killing and nothing else. Nothing wrong with the killing part of that; it's the "nothing else" that causes the pain.