Funny enough... I was playing around with different designs using the Bombardier MultiLevel as a base, as well as one inspired by the old Milwaukee Road equipment. Some notes:
Most 10' wide equipment can handle a perpendicular Full-XL mattress. Mixing parallel and perpendicular berths, you can get 19 Full-XL berths (and 1 Handicapped). 12 are roomettes and have no room beyond the bed.
However, once you hit Queen size beds, you're going parallel. Using my fictional (read: sci-fi/furry) band as a secondary basis for the design, I can fit all the road-going members in 11 Queen-sized berths (and some of them need the room). (Side note, because of some body configurations, the design has two bathrooms at ether end of the car).
"The last and final stop is BALTIMORE PENN STATION." I can has MARC V?