Definitely the Dolphin. The location is the best! You will be right by the Boardwalk/MGM/Epcot, and the transportation is excellent to all parks. Heck, you can walk to Epcot easily, and the Boardwalk is basically right outside your door. I imagine you will hit MK and AK on your days at the HIFS, so you can concentrate on the other parks during the latter part of your trip. The Dolphin also is very family oriented, and a Deluxe hotel with a great staff. Try to get a renovated room. The new heavenly beds are just that! Did I mention the great location??