I have taken many Amtrak adventures. The best is when my former wife and I took an economy sleeper coast to coast from LA to NY. It was lovely having our own small, but very comfortable, compartment. Three meals were included with the ticket. The food was absolutely wonderful. Also included was fresh brewed coffee and Danish every morning. I still went to breakfast in the diner.
Two-plus days from LA to Chicago, basically following old Route 66. A major stop in Albequerque, NM gave us a chance to get off and sample the wonderful and unique New Mexican cuisine. Before Albequerque a tour guide joined the train as it wound its way through native American lands. She gave a delightful and riveting lecture to a packed observation car as we passed stunning landscapes, a real highlight of the trip.
We met people, our fellow Pullman car mates, universally retirees. When you are seated in the dining car you are seated with others at your table, different people at every meal. The service was great; the food exquisite; the ride smooth and quiet. Best yet, we could board without taking off our shoes, and we had room to stretch out comfortably. (This is true also in coach.)
I would rather take Amtrak than fly any day. I like flying, but I despise traveling by air. It sucks! Amtrak doesn't suck.