I have never taken the train to the Canyon, but my husband did several years ago. He said there was a staged gun fight/robbery on the trip that was fun, and hee thoroughly enjoyed the trip.
I realize this reply is old, but as it regards the canyon, I thougght I'd throw in one other thought.
Camping in the canyon's campground does require a reservation, I belive; particularly in the Trailer Village Campground which has full hookups. I believe the others do not. However, I wanted to let you know that you can walk to the rim of the canyon from that park. Not sure about the others. The rim path is paved and lovely. It works well for us, as I have to use an electric scooter to get around, so we just get out my wheels and off we go. We take the dogs, and enjoy. You can go to El Tovar one way and to the gorgeous hotel, where the train comes in the other way. There are gift shops, and I think concessionaires for snacks and drinks.
Hope this helps.
BernerGran