I am not a fan of M3s or M22s with or without a sub. Alan and others, I am donning my flame suit.
Having said that, you can use your M22s for rears if you think rears will benefit you. 7.1 does not benefit me over 5.1. I should qualify that by saying I use QS8s for surrounds.
If you don't think 7.1 will benefit you, trade in your M22s towards a pair of M5HPs. I have not heard them but I have no doubt they will sound fantastic over the M22s, M3s and maybe even the older larger models like M60s and M80s.
