XLR cables for high-end multichannel system

No. I really wouldn't use a lesser quality speaker cable to the rears or surrounds if you can help it. I understand the cost factor may be part of the reasoning, with DTS master,HD audio, and all those fancy codecs along with your decent AV setup you have there you want to have a tonally balanced sound field around you. These days the surrounds are just as important as the fronts. I changed my surround cables last. I'm so glad that I did change them. The sound envelope (or cocoon) is just so much more revealing and you tend to "live" in the movie more.

Don't forget Stereolab/Stereovox. Very neutral.

Djruss: I've owned alot of Audioquest (Sky, Cheetah, Niagara, Raven, YIQ-5, Volcano, Mont Blanc, Gibaraltar, etc, etc...). Sky, Niagara and Volcano were my all time favorites. After multiple years using all for both home theater and 2-channel listening while I would say they are neutral in that they don't color the sound, I would mention that they are very revealing and depending upon your system, particularly with Sky, Cheetah and Niagra they may come off as a bit bright and potentially lacking in the deepest base. Given the right components though and making sure your system is balanced throughout, you would be extremely happy picking up Sky or Niagara. If you are looking for added and very large amounts of musicalism realism, energy, tonal accuracy, etc...you should also be looking at Kubala, Elrod, Purist and other top contenders. Listen first though to ensure you have the right match fro your system.