Do you have status with Hertz? The airport location with Ultimate Choice will be the better option for President's Circle. The airport location does include fees associated with the airport. Renting the car from the airport when you arrive and when you depart is much easier. $200 difference between the "cheapest" HLE location and the airport doesn't sound right. The airport locations are normally much more expensive, but much more convenient if you are arriving via air. Cannot imagine Miami would be all that different from any other large metropolitan area / airport.