I believe that the presence OR the rear surround work, not both at the same time, by the way...
But, I think that for sporting events, rock concerts, etc., the presence speaker is probably better than the 6th and 7th speakers in the rear. If you can afford to have BOTH the presence and the rear surround - by all means, do it, and pass on yoru impressions.
In re: the QS* issue. Here's the consensus ont he board. Go with the QS8s for the side surrounds. Depending on the width of your back wall, go wil direct firing speakers (which you can also mount in the rear with a full metal bracket). The direct firing are reportedly better for SACD and other 7.1 musical applications. Certainly, though, the QS8s will be fine, too, though, especially if you want a uniform look.
I think that I would go with the QS8s for the presence speakers too. Never having heard a pair of presence speakers, and not really knowing what they are supposed to do (I don't have mine hooked up with my RX-V750), I would think that they provide a nice, airy "back-foreground" mix that adds real depth to the front soundstage... The wide dispersion of teh QS8s is probably really great for that.
Be sure to tell us what you think, and also, please feel free to fill me in properly on the presence speaker issues, if I have gotten anythign wrong. I'm interested in knowing more about this.
