As I have stated before, in reference to the M^3, I am not yet a believer in active ground design. I fully intend to test this out when I finish my amp. When talking of the M^3, the three channels are already on board, but for something like the Beta, It would still cost roughly $100ish bucks to add an extra channel, and at this point, I don't think that is worth it. We shall see if I believe it in a few weeks, as I do some opamp rolling into the ground channel (as well as bypassing it).