Right, that's it!
a few days ago i connected 2 speakers in the back, expecting to have marginally better surround that what i already consider as very good in my 4.1 system (no center).
Well, after listening to TV and some music last evening, and then a movie today (all in 6.1), i told myself "that's it! now i MUST buy 2 more QS8's from Axiom, because the increase in realism is up by a good amount, and now i need really good back speakers".

the difference it makes is such that i will have to re-watch all my movies again, as if they had new sound tracks.