Without the ability to edit it as to 'window' and hold parameters, it isn't quite as useful as it might be...

I'd also like to see something more in the way of being able to turn parts on or off completely, depending on velocity, as long as you have that 'hold' parameter adjustable, because playing hard constantly, just to maintain the backing level is quite tricky. That way, one part might be a gentle strum pattern, and another a hard strum pattern, and have the arranger choose between them based on velocity

It's a great idea, and particularly in conjunction with the velocity switched V-Drums, can be very effective, allowing you the ability to get your drummer to rimshot the snare only when YOU get loud, makes an already pretty live drum sound sound even better... but just a FEW user adjustable parameters could make it better, IMO.