I've M60, QS4 and VP100 in 13 x 13 x 8 (roughly and open to kitchen and hallway) and I'm perfectly fine with the performance.
I went for M60 because I calculate by the time I get M22 plus stand and sub, the cost is not much difference. I listen mostly music and HT is around 30%.
Put it this way, set your budget and go from there. I don't think the difference is that much if any. We shouldn't stress ourselves to the limit (in my opinion only) just to get that extra 5% - 10%.
Wish you luck in your selection.
