I'm excited to hear how the quad master of this one sounds, hopefully it won't be as harsh as last year's Caravanserai SACD. I thought all these Sony Japan discs sounded great until that one, not sure what happened (different mastering engineer?).
The quad mix is quite different than Kooper's 5.1 remix in that it maintains all the hard-pans from the original stereo version - Bloomfield's guitar is off to one side on the first two songs, whereas it was centered in the 5.1 mix. Drums & bass are frequently placed in the rear speakers, sometimes each pushed off to opposite corners.
The experimental 'four-corner' approach is kinda fun for the instrumental jam tunes - you really feel like you're in the studio surrounded by the band - whereas some of the other tracks, like "Season Of The Witch", work much better in the 5.1 remix for me (Kooper placed the drums & bass upfront and guitar in the rear, while the quad has the drums & bass panning back-and-forth between the rears).