FWIW, I have strictly command for the most part, other than an occasional visit to conventional operation. I run the Fastrack switches from track voltage, each switch draws about 70-80 milli-amps from the supply when idle, it's hard to measure the switching draw because it comes and goes pretty fast. 
So, if you had 10 switches on one supply, you'd be at less than an amp of power for all the switches. This is at 18 volts track power.
EDIT: I just measured a single switch on the bench, and I'm getting 30 milli-amps, so maybe something else is drawing power that I'm missing on the track configuration. In any case, it's not much power.
