I have taken this train. It is some interesting scenery, particularly riding through the Mississippi Delta which is so geographically and historically significant. It is a relatively flat trip - no mountains to be found.
Deluxe bedroom is the way to go IMHO. Whenever I can, or if I am with someone, I get the deluxe bedroom. It comes with its own bathroom/shower and a decent amount of floor space. The standard/economy bedroom is OK for one person but too tight for two persons. Plus, the standard bedroom does not have its own bathroon.
Comp meals are provided in the diner as part of the use of either type of sleeping accomodation.