You don't have to imagine one track from Schmilsson -- "Without You" -- which was released on AF's The Collection SACD. Unfortunately, the Schmilsson album is pretty much a dud in quad. Not very discrete, lead vocal X 4, mediocre sonics, and lots of unmuted tracks left open sloppily. I never listen to it anymore, although the kitchen-sink over-the-top mix of "Jump into the Fire" was fun for a few listens.
"Court and Spark" is another story entirely. A top quad mix, likely audiophile quality. I say "likely" because until we hear an undistorted, non-CD-4 dub from the quad masters, we'll never know. But I'd sure like to.
Actually, it would be nice to get a few of the hard-to-find Nisson quads on two-fers. I'd buy them.