I took the Texas Eagle last spring going from Chicago to Houston and back. Actually for Houston, you get off the train at Longview and take a bus to Houston. The train I was on had a sleeper at the back, three coach cars, lounge car, dining car, then dorm car.
Going down I was in a lower level standard room in the sleeper. I was alone, so there was plenty of room, although I know some of the other people in those rooms were couples, and the upper berth in smaller in the standard rooms. Coming back to Chicago, I was in a standard room in the dorm car. I found out later that the dorm car was a Superliner II, and the rest of the cars were Superliner I equipment. I liked the room in the dorm car better, mostly because of the layout of the storage space. There wasn't that much, but in the Superliner I there was a real narrow closet, and in the Superliner II it was a more open space with a small rack. For storing my suitcase, that was handier. On the Superliner I there is one restroom on the upper level, and I believe it was three restrooms and the shower on the lower level. Being on the lower level made it closer to the restrooms. On the dorm car, there was one restroom down the hall with a small shower.
Since the dorm car is right in front of the dining car, it was less of a walk to get to the diner. They were showing movies in the lounge car, at night, but also during the morning, and it was a great place to sit and watch scenery, although on the Chicago to Longview stretch the most interesting scenery seemed to be in the St. Louis area, with the Mississippi off in the distance. I don't recall seeing much of Arkansas or Missouri, as going west we got to St. Louis around 10:00 PM, and coming back to the east, it was dark shortly after leaving Longview, as the train was delayed about an hour or so (part of that was because of a motorcade for Vice Presidetn Cheney who was visiting the Longivew area that day). I know I must have been asleep going through Little Rock both ways, although I recall stopping at Texarkana both ways.
I noticed other posts indicating the many things to do in Chicago while waiting between trains. If you have a lot of time to wait between trains, and the weather isn't too bad, going over to the Sears Tower observation deck would be worth it, but not if its real overcast. The visibility might be next to zero up there. If its a bright day, its a great view.
Have fun on your trip. dh