And what advantage does this have over the all-roomette arrangement proposed above, with 40 people?
I see a lot of roomettes with but one passenger in them. An all roomette car carrying only single passengers can hold 20, since Amtrak doesn't randomly share people in roomettes. The Slumbercoach can carry 38 individually ticketed passengers.
Were I in charge of Amtrak's sleeper program, I'd be running the single-level long-distance trains with 1 "Deluxe" bedroom car, 1 standard Viewliner, 1 All-Roomette car, and 1 Slumbercoach. That would provide for 10 Bedrooms, 2 Handicapped rooms, 32 double roomettes, and 38 Slumbercoach roomettes. This provides for a maximum 168 passengers, vs 128 with a set up of 4 Viewliners, which would provide 4 H rooms, 8 bedrooms, and 48 roomettes.
However, if we assume that 50 % of them contain one person, then that train carries 96 people. Whereas, my configuration would have 15 in the bedrooms, 4 in the H rooms, 48 in the roomettes, and 38 in the slumbercoach, or a total of 105. So on that level it better utilizes the space on a more realistic configuration. However, it also helps with space utilization on another level. Because single travelers would more be more likely to book duplex-roomettes, it leaves more double-roomettes availible to parties of two. So while I think 4 current Viewliners would normally run with a complement of about 96 passengers, mine would normally run with more like 120. 24 paying sleeping passengers is nothing to sneeze at.
I would even carry the new configuration a step further in trying to attract the wealthy traveler by turning 3 bedrooms into 2 nice, big ones and raising the price by 60 to 70 percent.
The Bedrooms can be opened up into "Bedroom Suites" by combining two adjoining bedrooms already.
I think the Sleeper Lounge is a badly needed facility for the LD trains which use Viewliners.
I envision it as being the place where the refreshments (coffee, juice, water, etc) can not only be accessed, but also offer a chair or two, to sit away from one's roomette (or I guess bedroom too). One of the things I like about Amtrak LD trains, are the people I meet. Today, that is really limited to being seated at the same table in the Dining Car. A Sleeper Lounge would offer another opportunity.
All Amtrak Long-distance single-level sleeper trains carry a lounge car, save for the Cardinal.