@chorus - I’m right there with you.
I’ve owned my pair of SC-III.As since 2006, and the only speakers I’m looking to upgrade to (but doesn’t make financial sense, with two kids coming out of private school and headed to college) are WATT/Puppy’s. Their dynamics, spectral balance, and immediacy are characteristics I can’t find anywhere else. In fact, I’d say the immediacy of the Dunlavys best the Wilsons, but the latter does everything else a little better than the former.
A friend and I were sitting in a high-end audio shop just chatting, after perusing the eye candy in the room. One of the salesmen (the same one who allowed me to bring home Aragon and McCormick electronics for overnight auditioning on just a photocopy of my DL) wordlessly walked in and got a CD spinning of the Eagles. The first developed riffs of Hotel California immediately shut us both up - we had never heard anything that close to a live performance (for reference, it was a CAL transport/DAC through Threshold amplification - forgot the preamp, unfortunately).
My cousin has a pair of the SC-IV.As and loves them the same. We both have rather largish listening rooms, but the SC-IV.As seem to over power his. He hasn’t treated his room yet, much to my chagrin. He’s still trying to tame a large bass suck out - mainly due to the top/bottom extreme placement of the woofers on the SC-IV.A.
It appears the overarching concern is the condition of the speakers due to age. I believe John primarily used Vifa drivers, which should be pretty durable. I’d go over the condition of the speakers with a fine tooth comb, but wouldn’t think twice about buying them, given good condition and a good price. I also would hold off on the IV.As if you can, but that’s not a must. As good as the IV.As are, if the straight IVs are even just 75% as good, they’ll still be a treat to listen to.
Good luck!