By Coastliner, did you mean Coast Starlight? I'll guess you meant the Starlight, for that train.
Sunset Limited(between San Antonio-LA)/Texas Eagle(SAS-Chicago) would probably also be interesting trains, to ride. The only annoyance about Sunset is that it sadly only runs 3 days a week, vs. Amtrak's other trains. And it takes an extra day(Sunset/Eagle) to ride between Chicago-LA, vs. Southwest Chief which only takes 3 days between those 2 cities.
The only small thing that was a tad disappointing about the Cardinal as much as I enjoyed it's scenery, was that it ONLY has a cafe car as of now and no dining car. Other users on this board supposedly have heard rumors that this train may get contemporary dining as of start of October, but I guess we'll see what happens on that(fingers crossed) when Oct. '19 hits. I rode the Cardinal east (but not west, as I rode in a car w/others back to Chicago) to Culpeper in May, and I remember by when we passed Charleston, so many cafe items had sadly ran out. I would bring some snacks onboard the train that don't require refrigeration(i.e. granola bars), to be safe. And I like to have a good meal and bring some leftovers on the train, to be safe. If you still fang for any food, during the extended smoke/stretch stop in Indianapolis, there are vending machines downstairs you can use. Also at least for the westbound Cardinal (as that stop is a little longer, vs. going east), if you are quick there is a White Castle kitty corner away where you could run to for food to go. ALWAYS listen to the train crew, and of course you never know if any of the stretch stops are shortened or eliminated due to the train running late. Stretch stops for this train are Indy (obviously), Cincinnati, Huntington, and Charlottesville. Not sure if Charleston, WV is ever called as a stretch stop, but I sometimes wonder if it occasionally is.
Food things aside, the BEST stretch for Cardinal route scenery IMO is between Charleston, WV and Staunton, VA. I LOVED that portion so much, and between Montgomery and Thurmond you'll very briefly see the New River Gorge bridge on your right(going east, on the left side going west) for a brief period of time. I posted a lot more details about my recent Cardinal train trip, with some photos(and will post more later), over in the trip reports board here. I haven't yet ridden the Card west, but if I do, I'd be a little curious to see the area around Lafayette, IN in the daylight, including its station house. ETA a link to my thread I posted, about my recent train #50 Cardinal trip(where I only took it going east, but not west as I had a ride going back to Chicago):
https://discuss.amtraktrains.com/threads/cardinal-trip-report.75324/
Hope you have a great Card trip, soon. And like I said, look up my thread about my recent Cardinal trip in May, on the trip reports board here. Side note: I'm jealous you got to ride Zephyr, Starlight, and the whole route of the combined Sunset/Eagle(and Eagle by itself), and I hope to ride all these 3 trains someday. I have ridden Zephyr to Denver, but not west of there just yet.
