I agree with the Tennessee Traveler. After several trips on the CS, I like the idea of a sleeper-class lounge car, but I'm fine with getting rid of the PPC. The best seats are clearly the swivel seats, and on ALL my trips they were hogged by groups almost the whole time.
Some combination of the SSL's large windows with the PPC's swivel seats would be ideal.
Here's my other idea: replace the PPCs with a remodeled SSL. Some combination of the SSL's large windows with the PPC's swivel seats would be ideal. Use the downstairs area as a kitchen, & cook and serve "REAL FOOD" from there for the sleeper pax. Then, add this car to all LD trains for sleeper pax only. Then, redo the dining cars as a more casual, cheaper, take out" - style alternative, mainly for coach pax.