Accardo and Costello have charm and seem approachable. That Genovese, he seems like he's always up to something even when he's smiling.
Vito's problem was that he was a street Neapolitan, always scheming. Worse than a Sicilian..
in the book "Havana nocturne" it talks about the meet in 1946 I believe when lucciano came over from Italy, lucciano always hated vito, never trusted him, in the book it says lucciano beat up vito in a hotel room, another book." the last testament of lucky lucciano" the same thing is related, vito was a real snake to those who knew him, and unlike other dons, vito would kill at the drop of a hat.
