My club (Florida Citrus Model Train Society) used Atlas track on painted 3/8" plywood decks for their modules, which are 48" long by 31-1/2" deep, perimeter framed with 1x4's, standing on 2x2 legs. Since all of the modules are built w/o roadbed, I have no real comparison, but I doubt if the noise level is much different, especially if tracks are screwed down and ballasted with both types of construction. I do know that using extruded styrofoam board as a layout deck rather than plywood can be much noisier. A friend has both types on his HO layout, and there is an audible difference when the train crosses from one surface to the other. The foam is much noisier.
Bill in FtL
