We did the Bahama Segway Tour and loved it! The tour was not through Disney but we did not have any problems at all. The youngest in our party was 8 and the oldest was 80 and every single one of us would do it again.
Make sure you don't do the city tour as that is just riding around on sidewalks. We did the tour where they take you out on nature trails and then over to the beach. The segways were easy to learn how to ride and the tour guides did a great job of giving us some of the history of the island, letting us pick out conch shells to take home, and giving us a beach break.
If you have any specific questions let me know.