I usually use one, but am new to the whole treadling thing. My W&G cabinet is very narrow and I am apperantly not so narrow so it's hard to fit both legs in there. When I do I usually have to sit a bit at an angle. I do use two though because since it doesn't have a permanent spot in the house yet it scoots across the floor becaus I havent put anything under the wheels. (and the machine is so small and light it adds no weight at all to the cabinet!) I also use two to start and stop the treadle but once I get going its usually one. I'm still learning and two works well too.
