I've withdrawn JA many times and have always been charged for Jamaican, not USD. Our last trip, it was difficult to get JA cash from the ATM's, tried many on diff days. Next trip I'm getting it from the bank before I go, I can order all the small bills I need and it's worth it for me to not have to worry about walking to an ATM to get more. The difference in the exchange rate is minimal; for me, the convenience outweighs the small difference - I don't get excited about saving just a few $$