We're staying at the Sheraton Boston and then renting a car to drive to Rhode Island for a couple of days. So it would be very convenient to use the Hertz counter there rather than going to the airport. We have a $50 credit from Hertz for them not having our requested car the last time we rented a car. Does anyone know how big the Sheraton Hertz counter is, if they have a fair selection of cars, are they open every day?