Great job. I do disagree on the use of the white "beaded" insulation board. It works well for larger scales. Not very realistic with N-scale, but with Ho and larger has its uses. He did make some good points as to why he uses the other board.
One of the great things about foam insulation board vs. the plaster scenery is the weight factor. I use both and usually use the foam board on larger modules. Plaster scenery also is more prone to damage and harder to repair. The foam scenery is more easily repaired. I also use foam board as the base for all of my modules. Care should be taken as to prevent "rumble" when using it. Making sure that it is securely in place is a must.
This guy obviously has too much time on his hands. Nice layout.