The thing I find severely lacking in 2-rail is a decently priced DC power supply. Are there any under $100-150?.
If 3-rail was running from a DC PS, I wonder what "system" would be in use now? It's odd they still run off AC and have to convert it to DC, seems like more expense.
With my 12x12 room I can barely fit an around the wall layout in it, practically no room for any type of winding thru the countryside track work and keep the benchwork 24" wide. If I go wider then the aisle width suffers and it's harder to reach across.