She may miss the WOW with the M80s compared to the M22s in your smaller room, my wife did Her only comment was that they sounded better than the M60s when compared to the crispness of the M22.
I am going to go out on a limb and say spend your money else where and a 7.1 setup may not even give you more WOW factor. maybe increasing the subwoofer abilities would give you more WOW.
I think my sub is doing a fine job, I just find my front a little bit thin. I'm also puzzled to find how the m80 sounds when you know how good the m22 is.