The main advantage of the QS8's is power handling. In a small room such as 12*12, using the QS4 in a surround application I would not think there would be any significant difference over the QS8. In a big room I think the differences would become noticeable.

BTW I use the QS4's in my system, never have listened to the QS8.

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne