I was always surprised that there were no Rundgren or Utopia quad mixes released or unreleased, given not only Rundgren's known interest in surround, but also because of the fact that there was a news item in Billboard circa sometime in 1973 (which I can't find at the moment) that said he was in the studio doing a quad mix on some kind of sound effects or intro tapes for the tour he was about to launch. You'd think if he went as far as carrying a quad PA on tour and mixed tapes for playback at shows that he'd also have mixed some of his studio work in quad, but I guess stranger things have happened...