I lived in New York during Dinkins AND Guiliani, and learned to appreciate Guiliani. Except that he chased the chestnut roasting guys off the streets, the idiot. I loved those things.
I've lived in the New York area for most of my life. The problem with Giuliani is that he can only function in a "crisis mode" in a jurisdiction that is normally run by incompetent leaders. He would be a marginal leader at best in any other part of the country, and most Americans would find the guy utterly unbearable.