Well this is only my opinion of course but the QS4's are not bad by no means. I originally had Paradigm ADP's as my side surrounds. I switched them for a pair of QS8's. What an improvement. This was at my previous residence but have since downsized to a smaller home and had to place the QS8's on my rear wall (no other choice except for ceiling) and placed the QS4's over my rear archway. The 4's quite honestly are not near the sound quality(oomph if you will) of the 8's but IMHO the rear channels for me only come into play on Blu-Ray 7.1 and they do a fine job with that. I am looking at the aspect of rearranging the 8's while I search for a new front stage. So my opinion is, if you can swing it you would not be sorry with the 8's as opposed to the 4's as your rears. I might add that I picked up the 4's from the factory outlet at Axiom and could not find a blemish on them and they are sonically perfect. Good luck.