The Sanders is very much a "sweet spot", near- or almost near-field speaker which also should be bi-amped (making the panels direct drive from the amp, no passive Xover). Used this way, for one listener, they present an astonishingly likelike illusion of real sound. True, very much not everyone's cup of tea (not mine, either), but if you are happy listening that way (Phelonious Ponk?) they are tough to beat no matter what the expense (not impossible, just tough).
All this is very true. I own the Sanders 10C. I would add that the Sanders is one of those speakers which you intellectually conclude can "present an astonishingly lifelike illusion of real sound," but which is simultaneously somewhat lacking in emotional involvement. I "like" and can get "involved" in the sound of my vintage ARs and Harbeth M40.1s better, sometimes much better. If that makes no sense . . . never mind.
I am much more willing than many to admit that I suffer from "the grass is always greener on the other side" syndrome when it comes to audio equipment, especially speakers. This applies not only to speakers I would like to buy next or would like to buy if I had the money, but most strongly to speakers which I used to own or still own but don't currently have set up in one of my systems. My newest purchase is not always my favorite, at least not after the initial period of infatuation is over. And, believe me, I can get infatuated with a new pair of speakers. With the Sanders, however, there was NO period of infatuation. It was strictly intellectual respect/appreciation right from the start. The "raised hackles" quotient has been very low with these; they just don't get to me at the primal level.
I plan to make one more foray into the current high-end speaker world before "giving up" and concluding that AR got it right enough 40 years ago and relaxing with those for the rest of my time on this planet.
As for more current designs I own or have owned, the Harbeth M40 and M40.1 are probably the best overall for a wide variety of music, but especially classical. If those seem too warm/bloated to you, then the Gradients are a way to go; I've owned/do own those, too. If a bit-more-lively but still quite neutral/natural sound is your cup of tea, try the PSB speakers--even the most expensive ones are only $4k a pair. If you want really loud and clean and like to rock but still want a "natural" tonal balance, try Legacy Audio Focus, Whisper, Helix (I owned the Whispers), or the JBL Pro LSR6332 + JBL LSR6312SP subs, the Volti Audio Vittora or Volti-modded K-Horns, or at bargain-basement prices and with a cheap EQ device added, even the Cerwin Vega XLS-215.