Just acquired a shed with 10X8 space for train layout. Oddly, I want two layouts: (a) my HO Era-2 German layout {that I had to tear down - moving} and (b) an OO scale British Great Western {that I want to try}. The question: do I build a double-deck round the walls or do I try two equal 5X8 with one six inches lower as they both traverse the foot wide overlap at the five foot mark. Obviously the other three walls will carry +/- 20" decks so I can fit in the two donuts. The advantage of the round-the-walls is, of course, longer runs but the disadvantage is less scenic opportunity on the lower deck. The disadvantage of the two 5x8 is obviously less operating potential but the advantage is greater scenic opportunities. I'm not asking for help designing the track layout (German & British are both different from USA), but I would appreciate any thoughts, especially based on experience, of the two options. Oh, btw, can one REALLY use LED rope lights from China for a 20-24" wide lower deck?? Thanks for taking the time to read this odd question.