Hah! The credit card rewards ruined these. Now they're all crowded and it's just as hard to find a seat as it is outside the lounge. Plus the food in them isn't that great anymore. The best benefit is usually a better view out the window. Real frequent fliers just get PreCheck+Clear and arrive at the airport closer to departure time.
I did this same train journey myself back in 2012. Great memories! I just wish 2 things:
1) Amtrak wouldn't recycle the air on train carriages, it gets really stuffy. The downstairs washroom smells get mixed in too.
2) Single riders should be given both seats on these journeys. I was like 19 when I did this journey and an unusual middle aged lady was placed next to me. She kept asking me for medicines and fell asleep on my shoulder.
Riding through the desert outside of Albuquerque during sunset was the highlight. Walk all the way to the back of the train, look at the back window, get a rare listen of the jointed (not welded) tracks. Here's my video of it -https://vimeo.com/57261056