BLUF (Bottom Line Up Front): This is a long description of my strange trip, and it responds to the OP only within the domain of vintage Mc tube gear. I don't expect my experience to be any kind of "guide to absolute truth", but it is one data point.
I LIKE MCINTOSH SEVERELY
I used to use Mc60 (tube) amps, and now have Mc225 and Mc275 tube amps. I rotate the 275 with four other solid state Mc amplifiers, including the revered Mc7270, so I think I understand the Mc sound. I surely agree with atmasphere, that the amplifier should have *nothing* to do with the sound one hears. However, that is an ideal which I myself have not approached. Source, Speakers, and room do have more "going on" with what I hear, but I hear the Mc power amplifier sound too. The point of this paragraph is that I am an Mc fan for sure, although I do not insist that their products are perfect.
MOST OF MY SPEAKERS ARE VINTAGE
Speakers I have used for a long time in my homes include Altec VOT (four, no less), Dahlquist, Maggies, even Bose (for a time), Electrovoice, and now, most usually, Martin-Logan electrostatics and Vandersteen 2ci. Looking back, the Altecs I had -- in a somewhat huge room -- did not provide the best experience where clarity and dynamics are concerned.
CLASSICAL IS NOT ATOP MY STACK
I do not often listen to classical orchestra music, but I do have a handful of favorites; some/most of those are pressings from 1950s recordings. Fanfare and 'Burana come to mind. My impression of classical music reproduction is that low-amplitude (that is, low SPL) passages are very usually reproduced incorrectly; that may ruin the genre for many people. On my SS Mc systems, very quiet passages seem too loud and lack tonal quality throughout the spectrum. I attribute this to a choice of design values held for the last sixty years or so at McIntosh. I'm not trying to do any bashing here -- maybe I listen with a too-low volume setting to begin with. This is my experience, and of course yours may vary a whole lot.
I remember that on a winter day maybe thirty years ago, I played classical music through the Mc60s (alas the Mc60s are now in storage) into (passive) Magneplanar MG1s. The room was maybe 16' x 24', with a cathedral ceiling and dense carpeted floor. I had one of those stopped-in-my-tracks moments that evening. The dynamics were correct. The soft passages were soft -- not crushed into grunge. No solid state amp -- Mc or other --- has come close to that experience.
My experience with "high SPL dynamics" is quite a different story. Through my Vandersteen 2cis, I hear the hardest undistorted hits and the most intense loud passages clearly when I drive them with my Krell KAV-300i. Go figure that. For high intensity, that 300i does better with the Vandersteens than my KSA-250 or my KSA-200S.
So what. Vintage Mc60s, driving vintage planar electrostatics provided the most correct dynamics -- and thus the most involving musical playback -- I've experienced, but only for one night in memory. Vintage Krell is not what the OP wanted to know about, and except for the Martin-Logans, my speakers are all very old.
I do think my equipment hygiene is good; I make distortion and power measurement tests, balance listening tests, and I've funded two excellent techs through their careers.
Enjoy the music.