my own anecdotal experiences are quite the opposite. new yorkers are more open, tolerant and curious (w.r.t my being from a significantly different culture) than people i have met in the midwest, northeast (where i lived for three years) or the south. people in the midwest or south (and even new england) have been more polite (when they are not racist ;-)) but i often got the feeling that the politeness did not extend to the natural sense of being treated an equal (which i get in NYC).
perhaps it helps that i agree that no place on earth is better than NYC ;-) (though there are places as good: london, various parts of utah...)
--ravi
p.s: i am mostly talking about manhattan when i say NYC (only because that's where i have spent the most time).