Remember, since GPK has baggage service you can check bags through to your destination, they will be transferred in Chicago for you. (to/from WAS not BWI) Whatever you need to travel with, pack separately in carry on since you will not have access to your checked luggage enroute. The Superliner sleepers have luggage racks downstairs where you can store whatever you don't feel like having in your room. Lots of people will leave a "change of clothes" type bag downstairs for convenience to the showers. If your train connections allow (time and weather) both Washington and Chicago have bag storage for anything you did not check. They are not attended, but there do not seem to be any frequent problems, but like your bags on the train, many people are more comfortable with things like laptops, cameras, prescriptions, close to them and will leave some things in their room on the train or carry them. If the CL is relatively on time to Chicago, and the weather is nice, get out and do something, look at some of the threads about layovers in Chicago for suggestions, but be aware of the time you need to be back....most of all, relax and enjoy.........this type of trip is great for decompression....