I just want to be as far away from the locomotive and its horn as possible. I rode the Texas Eagle to Los Angeles and it was great being in the last car from San Antonio to LA. Likewise the Lake Short Limited has it's NY sleepers on the back.
A few years ago we took the Empire Builder from Portland to Milwaukee. We were in Bedroom D and the last car on the train consist. Because there was no other car connected to the back of ours the swaying back and forth was terrible. It was very difficult to sleep/move around because of this. Unfortunately, because there is often only one sleeper on the Portland to Spokane section this is sometimes impossible to avoid.