I started with the intent to try for a 5x9 layout, but the track almost by not quite fit, too many compromises and the grade became steeper, so I ended up with a 5x10. I might look at an extension to make 5x12, and see what that does.
Still to add a couple of streams, and perhaps a waterfall.
Subjectively, the plan has a satisfying balance between track-work, scenery, and structures.
