simple, doing it's job. I use it to connect guitar to 2 amps simultaneously and enjoy "big" sound, but it can be used for other functions as well.
there is one thing that is not exactly as listed in specifications. there should be red LED light when only A selected, green for only B selected, and yellow for A+B, but in reality with A+B there is no yellow light at all, only green light with small, hardly visibe dot of red light at the same time. no big deal, but it shouldn't be specified that way.
of course, pedal can work without power. when A+B option is used, footswitch and LED light have no purpose anyway.