i love the grand floridian spa - it's much smaller than the saratoga springs one - which i prefer.
no matter what massage you purchase, you are then entitled to use all of the spa facilities, which includes a jacuzzi and sauna. And since it's in the locker room area, you're in the jacuzzi/sauna only with other women. (i assume the same is true on the men's side - i've never been over there to know).
you can also use the workout room, if you're so inclined - treadmills, weight machines, etc.
i've gotten manicures and pedicures there - they have a separate room for that, with wonderfully comfortable chairs.
DD also has had massages there and enjoyed them very much.
From what i remember, the same company (not disney) runs both spas (at saratoga springs and the grand floridian).