I though JS was pretty well known in Europe and Latin America, too? Certainly he's had several Presidents and high profile officials on.
KA and QR tend to make more visits to the US than other royals any particular reason?
The King was there when the Israeli/Palestinian peace talks started and he usually tends to speak to the President about it when he is there. They are both usually there in September because it's the UN General Assembly and the Clinton Global Initiative as well as other events around this time of year. There tends to be alot of events/conferences/meetings in NYC that they attend.