Use the Impulse 61 as part of my live setup with MainStage. All the faders, buttons, knobs and pads map easily to MainStage. A minor gripe is that in order to use the transpose feature you first have to press both transpose buttons then use the knob to the right of the display to change the value. So what should be a quick left hand affair becomes a much longer sequence. If you play live and have to change keys of a song on the fly, you'll understand why it should be as quick and with as few steps as possible. A major grip is the action of the keyboard itself. The reviews I've read dubbed the action better than the SL MK II