I'm not sure where you'll be coming from but I would say not worth driving far as a sole destination. If you are passing through or nearby then yes it's fun to stop at this historic diner. Food (featured on TV's "Diners, Drive-Ins, and Dives") is "diner-with-a-twist" and a few daily specials (lunch and dinner) usually w/ an international theme (e.g. Greek, Mexican).
Sample menu should be accessible at www.a1diner.com