Yes...the Segway tour is fantastic. My wife and I took the tour last December. The first hour is spent inside a "training room". You learn how the thing operates and you get to learn how to ride it. You practice going around cones and up and down inclines. Then, after a restroom break, you go out and go all the way around the World Showcase. So nice to do something like this when there is no crowd.
The hardest part about learning to use it is keeping your balance. Everyone is used to a bicycle where the rider must maintain balance. This is totally different. It measures your body position and readjusts itself underneath you 100 times per second. So, if you are trying to balance it yourself, you will be actually fighting against it. Just relax and stand on it. Let it do all of the work.
The only other thing that you need to think about before you go is the physical strength in your legs. Although you are moving around, in reality, you are standing in the same spot for nearly two hours. (Try standing in one place in your living room and you'll soon realize how tired you get.) When you get comfortable with your Segway, you'll learn how to stand on one foot while you stretch the other leg. But, it is still difficult to do. The first thing that my wife and I did when we got off was go to that McDonald's french fry place near Canada, ordered a couple of large fries and a coke...and SAT DOWN and RESTED.
With all that being said, it was a lot of fun and we would do it again in a heartbeat. Have fun!