We took the train from Williams to the Grand Canyon seating in the Dome Seating. The view from the dome is great, the scenery is interesting but not spectacular. You don't see the Grand Canyon from the train, it only takes you to the south entrance of the Grand Canyon. Once there you will want to use a tour bus to see other interesting points in the south rim area. If you opt for the Dome seating, refreshments are provided, breakfast items on the trip to the Grand Canyon, snacks on the way back to Williams. There is enough to eat on the train that you don't really need to buy lunch while at the Grand Canyon.
The staff on the train was great, they provide information about the Grand Canyon prior to your arrival at the Grand Canyon, provide entertainment on the way back to Williams, and a champagne toast before your arrival back in Williams. Seats are really comfortable.