I have to agree with Mike, if you can make it 5 feet wide, 054 curves will let you run a few more engines and longer cars. Even trains with shorter cars and engines look better. My layout I am building is around the walls in an 11x11 room, so it is a different animal. However, I am very happy with my decision to find a way to put in 054 curves on my twice around plan.
Mike, the photographs look great (as I expected)