matt, sent a pm, don't know why it was not received. i'm in pembroke ma, near plymouth, if you are interested in a road trip. i have: m60, qs8, vp150, ep350 dan
I said this because, in a lot of cases, channel "A" utilizes the sub (and how levels are applied) differently than channel "B". Switching between A & B may not only give you different volume (or EQ) levels, but may also change the LFE and xover characteristics (this is why I prefer a switchbox).
I've had the m50s and the m22s. The 50s are more laid back, while the 22s possess greater clarity, detail and soundstage. Initially, you might not notice this, but after a couple of weeks the differences become blaring. I kept the 22s.