I did the Segway Tour on our trip last May and loved it.
The time in the building, learning how to use the Segway and practicing was great, our instructors/tour guides were wonderful.
They gave us more than one opportunity to change our minds about going and one women took them up on it. You have to show you can maneuver the Segway in certain situations and listen to instructions from the guide, or they reserve the right to say someone can't go on the tour portion around WS.
I haven't heard of this happening, but can understand why they have that option.
Once we left the room we were learning/practicing in, we made our way on the Segways to WS, cruising right through the crowds with people clapping and shouting "Where do we sign up to do that?" and "Is that included in our admission?".
In WS we went through each country, spending more time in some than others.
We hung out in Italy for a while and had time to just cruise around on the Segways. They had roped off an area for us, this was also a great time to get pictures.
I was on the second tour of the day and by the time we made our way in the American Pavilion, WS was open and we were maneuvering through crowds again, which was not a bad thing, but required more attention to your surroundings.
My husband and 2 year old had been waiting to see us go by from the American pavilion and followed us back to the building we started in.
Once we returned we were pretty much done. We got a pin and that was that.
I had a wonderful time and would do it again, although I should let hubby have a shot first.

I found my feet were sore by the end which surprised me.
Since your are leaning forward to go and backward to stop or go backward your are distributing your weight in a way you may not be used to...at least thats my theory for what I experienced. So wear comfy shoes.
The Segways have bags on the front for your personal belongings (camera, purse, etc). And there was a chance for a bathroom break before we left for the WS part of the tour.