BIGGER is always better. I run a 8'x 12' train board at train shows. Most of my motive power is post war and/or pre war. So I use post war
ZWs. I have three loops and am adding a fourth. I run two loops on one ZW and will run two loops on a second ZW and keep a 3rd ZW
for my two test tracks. This photo is from my older board at the 2010 Syracuse Train Show. I have since scraped that board and built a new board.