The M3 Sapphires are so good that if you purchase them you have to take the time to allow them to settle and a breaking-in. You also have to rethink, speaker cables and power cords that you built around your old speakers, that you took to the time to bring the best out of them.
What worked with my Quads work well with the M3's but after going to my closet of saved speaker cables and power cords, I inserted different ones and took note of the changes #1 these speakers can really do bottom end, from to much to, to light, depending and the speaker cables, I finally found a good match with Analysis Plus Black Mesh Oval 9, power cords to the Amp PS Audio AC-12, same to the front end gear PS Audio re-generator P-12, from the 2 PS Audio Signature SC power cords, with interconnects True Balanced Premier SE XLR Analog Interconnect.
These replaced other cables that brought out the best in my Quads which were limited in the top end extension, so my selections were cables that max out what the Quads were capable of. These were LessLoss Marc-C, Nordost Valhalla, C-Marc Power Cords, and Reference Power Cords (All good, C-Marc special). So big $$$ cables replaced to bring out the best of the M3's. Now I have the midrange clarity and naturalness of my Quads, but with a more extended top end that is now natural, and deep, deep bass and good midbass finally. I made the changes and then reverted them back played a recording of the Cleveland Orch. My wife used to usher at Severance Hall and knows the sound under George Szell quite well. Brahms Violin Concerto Violin Sonata No.3 David Oistrakh Violin.
Played the tracks once with my old setup and told her to listen, made the changes all at once, and replayed the same tracks, Within a minute she said that is much better, and once the movements got going and the full Orchestra came in, she said: "Now that is amazing, that now sounds like the Cleveland Orch". She said the warmth of their sound, the Violin has the sweetness, and the rosin details much better, not in your face to where you don't notice the Orchestra, lower Cellos, and Violas are now there. She said amazing the ear you have and how cables could impact the sound to such a degree, she said you guys are nuts! Smile! So from my experience now with these speakers a few months almost, I can say they are what you feed them and what worked on your last speaker, may or may not work as well as possible with these speakers. My own experience is my systems and others, we are like good cooks, the experienced ones know how to build a system, and to bring out the best in a system, and much like the cooking and spicing it to our liking and the added plus for sound the accuracy to the point where if you know the sound of a live performance and the sound of the Orchestra.
From day 1 till today the is no comparison of the sound today, they went from sounding good to sounding superb. The factor is the cost, these are way best good, they can sound like speakers with the boxes that would set you back 25K and not sound as big, and natural and I have auditioned them, and every time said to myself boy my Quads kill these in so many ways. I can say this about the Spatial Audio M3 Sapphires now.
To end. The guy who purchased my Quads ESL 63's owned the Quad 57's and his cables were built around those speakers, with the Electrostatic Solutions rebuild of my 63's which have more extension top and bottom, compared to what he heard at my house, they sounded a touch thin. I knew what speaker cables he used and I had tried them myself and did not like them, I wrote him to say purchase the speaker cables that I used for my Quads, he did and wrote back much better, the thinness is gone, and the bass is much more present and fuller, the same situation new speaker may need a new setup position and different cables to bring out the best in your new speaker. He also needed some corner traps and a few other panels for the front wall behind the speakers, a brick wall is never good. The 57's does not radiate from the back as strong as the front like the 63's, so that is a change he will have to make to get them to sound like they did in my house when he picked them up. He will get them right I'm sure.
So if some say the M3's sound hollow, or bright and forward, that not necessarily the way it has to be, it's telling you what you feeding it with and is just giving you the sound you sending to the speaker. Now I can sit back and relax, oh by the way I played a big Band recording this morning and it blew me out of my chair almost, dynamics, weight and power of the horns, and the feel and swing of it all were there in spades. Not just the "sound" of recorded instruments, but the real instruments with color and tone much like the real thing.
Hope this helps all.