All of my discs are 7.1 thanks to Dolby Prologic IIx. That extracts matrix encoded audio or ambiance (Movie or Music mode respectively) from stereo tracks and spreads things around in a very convincing manor, or steers the surround channels of 5.1 mixes to the rears.
In all the other threads I've said, and I'll say again. With the QS8s to the sides of the listening area pans sounded as if they were going over head instead of behind me. But adding the 6th and 7th channels behind me made the movement of audio seamless. Right now I have my old monopole surround speakers back there, and the effect is good, I can only image it'll get better once I have a second pair of QS8s.
While you don't have any DVDs with more than 5.1, about 25% of Blu-rays being released today are 7.1, and that's probably only going to increase over the life of the format.
I like my 7.1, and wouldn't trade it for $500. Even if you don't make the jump right away, don't make any changes which would rule it out. The format, while not pervasive, is becoming more common.
