Joe Daddy, I completely agree with you on the hype with current loads from locomotives. All but two of mine are sound equipped and all (19) are always on the layout;there is also one lighted passenger train. With this static condition, my RRampmeter shows 1.4 amps going to the track. This value has been validated with a lab quality Fluke digital meter. When I start up locos w/consist, it takes 3-4 running before it will go over 2 amps. The 0.25 average per loco sounds about right from my experience. Not long ago, I had an op session on the layout that had 22 powered locomotives in operation with at least 16 pulling and the meter never went over 5 amps. (I have a Digitrax Chief 8amp)
The reason I went with 12awg solid for my layout bus is the size of the layout (double garage) and the convenience of being able to shape the wire to easily conform with bends and turns (solid). For smaller layouts, I cannot understand why all the argument about 12, 14, 16 awg when the price difference between them is insignificant for that short of length. Why not go with the larger and not worry about it? Just buy some Romex house wire, easily strip the sheathing and there you go. These same people will go out and pay $40 for a caboose, but worry about $5 difference (if that) in wire cost.
Joe/Larry: I also agree that the bottom-line is the workmanship that goes into the benchwork will determine how well the track/layout will perform. You cannot take shortcuts with this phase of construction. I have seen guys use 1/4" scrap plywood that wasn't supported properly, nor was it fastened properly and then wonder why it has warped and twisted everything. Or: Use BC plywood at 24" ctr joists, use just enough screws to keep it from sliding and wonder why their track moves. Personally, I use BC 1/2", 16" ctrs, and never spare on the screws.
One note: For those saying a foam layout doesn't have to worry about wood warping/twisting, well, the foam is secured to the wood...right?