I rate this a 10. I am a fan of the Grateful Dead, so the music is already a winner for me. Soncially it sounds as clean as a whistle to me, and the surround mix is discrete and adventuresome without being gimmicky. For instance, check out Friend of the Devil with acoustic guitars biased to the rears and David Grisman's mandolin isolated in the center channel. Mix wise I am not sure what else could have been done. I suppose one could mix instruments with more isolation - less bleed - but I think having some of that gives a very full and enveloping sound.
I just listened to the DualDisc and the DVD-A. The mix, volume level, sonics, and the menus are identical. Both appear to have the same bonus features. On Amazon the DVD-A is currently listed used for $45 and the DualDisc is listed used for $11, so this title can be acquired for a very reasonable price thanks to the unpopularity of the DualDisc format.