A few years ago we took the kids on Amtrak's Auto Train from Sanford, FL to Lorton, VA. Great trip, they really enjoyed it. I was disappointed, however, that our overall average speed was only about 50 mph for the trip and there are no scheduled stops on the route (one stop at about 2am where the operating crew is changed but no passenger stops). The train reaches speeds of 70 mph at some points on the route but it has to go much slower on much of the trip due to the track conditions.

Of course, in this case, I would have actually liked a few more hours on the train just to have more time to enjoy the ride but that isn't the point.