Michael, I think Mr. Brockman is correct. Even without getting luggage it would be very difficult to get to 42nd Street between 9th Avenue and Dyer Avenue (the location of the Acorn) by 4:30. It's rush hour both ways (coming and going to Manhattan) plus there will be lines for taxis. If you're at JFK and take the AirTrain (which would avoid the street traffic) you still have to get to the facility, take the train to Jamaica and then take the train (either LIRR or subway) into the city. If you're at LGA you have to get through the traffic in any form, bus, car service or taxi and most of them come through the Mid-Town tunnel which lets out on the east side. You will have to get across town from around 38th Street on the East Side to 42nd Street and 9th Avenue.