While Delta holds me captive for hours on end refusing to give me more than 24 peanuts at a time, I invest the time in designing layouts. My trip to Detroit (snow) and back gave me 3 hours of total thought time, minus a small argument with a bone head behind me that was playing his stereo too loud.
My big question for Jackson's layout is "can I get it all in and if I can't what gets dropped?" Big question. There are a lot of good features on the layout. One thing to consider is a good mix of traffic. There are a ton of industries that take tank cars so you don't want to be just tank cars running around. The Nelson Marble Cutting operation is back up and running. It doesn't take rail cars, but it is so cool to see the train run right through the middle of a business with all that white dust and stone.
I'm getting a good trackplan in my head now, but need to finish the drawing of the room and check it out. I NEVER start drawing without the dimensions being thoroughly checked. But we'll start soon.