I very much agree with you. I doubt you will hear anything as good going forward, either, including the subsequent Quad electrostatic offerings. Those that followed certainly sound different, and may have addressed some of the issues that folks had with the original. But they also took some things away. For many, including myself, a magic and rightness exists in the ESL57 that doesn't elsewhere.
@markcooperstein, "I still think a proper pair of Quad’s is the way to go. The problem is finding a pair! I’ve discovered Electrostatic Solutions LTD and if I get a decent looking pair intend to have them rebuilt there. I’m guessing after I find a pair and get them refurbished I’ll be spending between $4K and $5K. Unless I find a great deal on a pair that is already up to snuff."
You're right in terms of pricing for a rebuilt pair. Considering so many loudspeakers today carry the price tag of a good new car, yet don't bring near as much happiness, you've found something offering great value. Actually, they are pretty easy to obtain here, ebay, or the other sites that specialize in high-end audio gear. Best to stay patient, and give yourself at least a few months to land the right pair, though if they appear, don't dither. You don't necessarily need a pair that's already rebuilt. So many of those offered on the used market still work fine. If you come into some with no issues, use them and enjoy them. If / when the time comes for a rebuild, then you can cross that bridge at the point.
Finally, your Bob Latino amplifiers should mate with the Quads fine. A rebuilt pair normally include the protection circuitry. If you move on an original pair, remember so many drove theirs for very long periods of time without issue using Dynaco amplifiers back then, including the MKIII monos these are based on. Presuming you don't go nuts, the speakers should not have any problems