I've done the tour multiple times. Worth every penny. They are very helpful in making sure everyone is very comfortable in the scooters before they take off, to the point that the third time I took the tour I wished there was an advanced version for people who had already been trained.
If you do the tour, try for the earlier one in the morning, as it gets you a chance to see EPCOT's World Showcase before it's open to the public. Makes for some very cool pictures when there's no one in the background.