I'm just listening to this mix for the first time, and I'm blown away. I have the SACD and was really impressed with it, but I had no idea how much different, and in most cases, superior Parsons' quad mix is. Us and Them in particular is an entirely new experience. Did anybody else notice that there are saxophone parts in it that are completely MISSING from all CD/SACD versions? I mean right before the vocals come in, there's a bit of sax play that I never heard before and that's definitely not present in the stereo or 5.1 mix. The echoes that go around the room are spectacular, too.
I also noticed, though, that at the end of "On the Run", some of the maniacal laughter is drowned out by the rising noise, or simply missing altogether.
All in all, Guthrie's mix, as many pointed out, is indeed less aggressive, and many elements are far in the background while in Parsons' mix, they are distinctly audible and at the forefront. One example is the line "I never said I was frightened of dying" in "The Great Gig in the Sky". On the SACD, it is floating around somewhere in space, in the quad, it's right there, loud and clear.
Listening to the SACD was like hearing the familiar material again, just remixed for 5.1. It fit like a glove. This quad mix, however, provides a listening experience like it's really an entirely different mix. It's like tubular Bells 1973 vs. the 2009 remix. They're two distinctly different listening experiences. All I can say is WOW.
I SO hope that the other Quad mixes will some time see the light of day. As far as I'm concerned, don't even bother making new 5.1 mixes of the other albums. Just get the old quads out there. I'll be the first in line to buy them.