As nearly as I could tell, the only difference between the Tennessee Tornado train and an earlier Arrow looping coaster train is that the Tennessee Tornado train has the larger (12") road wheels. But Steel Phantom had those. The thing I noticed on Tennessee Tornado, though, was that I don't think there is any straight track on that thing. The transitions are far more gentle, with the curves carried out smoothly between elements. I suppose it is not inappropriate that the Tennessee Tornado be a curvaceous coaster... :)
--Dave Althoff, Jr.