Originally Posted By: Dr.House
I think a better upgrade in your case is to get a matching centre channel (Axiom VP150) which will improve the timbre matching with your M60's. This can help provide a more seamless front soundstage for your system and could provide a significant improvement.

I 2nd the recommendation. I feel between upgrading to QS8's vs upgrading the centre channel, matching up the centre channel to your M60's would be the most noticable improvement.

Epic 50 - 500 System ( M50 / QS4 / VP100 / EP500 )