Im not Andrew, but I would go no hotter than roughly 600 for NY style pizza. It also depends on where you are measuring it. Measured in the middle or the front or the back of the stone, measured at the back wall, what the dial is set to... they all mean different things in different ovens. Try dropping on a floor thats 600.. but again thats hard to quantify, because with one type of stone that is too much, and with another its not enough.
The true way to speak about bakes is in bake time. Most NY pizzas are in the 6-8 minute range with malted flour and the classic look. Some are even in the 10's but Joe's is on the faster side.