Besides the obvious looks, the biggest thing I would say is the fatter tire would be less apt to follow grooves in the pavement. A fatter tire has more contact patch with the road, better traction. Smoother ride due to the taller sidewall of a fattter tire. The thinner tire I believe is easier to turn. I have never rode a bike with the tall, thin tire for any length of time, just quick test rides on friends bikes after tire changes and such. These are just my opions.