From what I understand, the QS8s are a more perfect match to the M22s than what the QS4s are (the QS8s have the same drivers as the M22s). This allows the QS8s to play a little deeper, a littler louder, and fill more space with sound than the QS4s.

When I purchased my system, I was ready to purchase the QS8s. But both JC and Brent at Axiom customer service recommended that I buy the QS4s and put the money saved into upgrading the center channel to the VP150. Their advice I believe was absolutely sound...like I said, my room is very small. My head in the prime listening position is only about 5.5 feet from the QS4s. So far I have been extremely pleased with the QS4s...they can play very loud when they need to, and their unique design really creates an immersive surround field. I have often wondered how much better the QS8s would sound (especially considering they are only like $120US more than the QS4s)...but I try not to get hung-up on the "what ifs" and just enjoy the stellar sound.

I think that if you have a larger room or have the few extra dollars burning a hole in your pocket, you should seriously consider buying the QS8s.