What is the most overlooked consideration?

I suggest everyone here look up the meaning of "musicality". The "performance" and "composition", ime, is what I listen for, from my recordings. Timbre and tonal color, while important, has been changed from reality, once the mic and mixing console has been brought into the picture. Here is a question, as an example. Take your favorite musician (let’s use a vocalist for this), place this vocalist in two different settings. (1) a grand concert hall, (2) an airport bathroom. What will sound better? Now, take a mediocre vocalist who is not very good, and place him/her in the same two locations. What will sound better? I would always take the concert hall scenario for the acoustics, but if I was given a choice, I would rather listen to the better vocalist in the bathroom, vs. the inferior vocalist in a concert hall. This is me, and I look/listen for the performance 1st. What I am saying here is, I have heard so many multi thousand $ systems in bad rooms, and average systems in great rooms. Listening for the performance and composition over everything else, would determine which I prefer......and let’s not forget...the reality is, the recordings for many audiophiles, are the bottlenecks with the entire sq presentation. This is why so many listen only to those rare "great recordings", and pass, on some excellent performances and compositions. I know some of this might not make sense, but......comparing live, unamplified music to recordings, is a destination we will never get to......for timber, warmth, etc. The performance, and the composition....these two elements are in all of our recordings. So, buying a piece of gear, because it seems to get the timbre right? The timbre has been altered already. What about the microphones, the selected placement of the mics, and everything else down the line prior to our ears experiencing it....this is generally decided by the producer and maybe the artists........my current system is less expensive than what I once had (my choice), and it brings me greater enjoyment to the two basic characteristics I listen for. Honestly, this is some rant, if there ever was one. BTW, I would take the bathroom scenario any day, to hear the better vocalist, if it came down to it......whatever works best for you.......can you guess my answer to the question asked? My best, MrD. 

In a flawed by design stereo system (See Dr. Edgar Choueiri papers here ),

there is no "mythical" reproduction of the timbre experience, which is also not only a tone experience but a dynamic experience (the way the musician hands touch the guitar strings for example ) There is only a translation of the recording trade-off choices of the recording engineer room & micros parameters according to the acoustics parameters of your room system...

i dont listen to a dac, i listen to the timbre experience in real life and in playback to learn how to make an improvement in the acoustics parameters of my room to improve not the impossible reproduction but the acoustical optimal translation of the recording choices in my own room  ...

Acoustics rules audio not the reverse...

The performance, and the composition....these two elements are in all of our recordings. So, buying a piece of gear, because it seems to get the timbre right? The timbre has been altered already. What about the microphones, the selected placement of the mics, and everything else down the line prior to our ears experiencing it....

To answer the OP question i will write only one sentence :

 It is useless to buy a 5,000 bucks dac if this dac is not as most dac in most system properly grounded ...

The most important lesson in audio comes not from upgrading experiences contrary to what  most think  boasting about their gear pieces tastes (price and results);

It comes from proper electrical,mechanical and acoustical working optimization process...

It ask for time not for money, it ask for  acoustics studying and experiments not about  audio reviews study...

I never spoke of microdynamics versus timbre...you misread my posts...

Before blaming someone for misreading your post, take a moment to review what you actually wrote. Yes, of course — everything about sound is vibration; no vibration, no sound. But you specifically brought microdynamics into the discussion, which led to a confusing and incorrect statement.  Please do not misuse terminology here.  Microdynamics do not create or lead to timbral characteristics — not if you truly understand what you're talking about.

First Timbre pertain to the microdynamics of the vibrating object ...

i was speaking of the vibrating sound source, for example a vibrating violin, under the touch of a musician which total  resulting microdynamics created a timbre quality perceived differently from different location...

As explained earlier, timbre is tonal color of sound and is fundamentally defined by the spectrum of harmonics and their relative amplitudes. (https://www.britannica.com/science/timbre).  Therefore, harmonic content has more direct, effective control over timbre.  One can use various means such as choice of DAC/filters, tubes, EQ to directly / effectively shape timbre.  It is well known that adding or reducing second and third harmonics gives a warm or more clinical tone respectively — a direct change in timbre.  Here is an actual example presented by GoldSound in measuing one of the Smsl DACs.

On the other hand, room acoustics have an indirect and relatively moderate influence on timbre. While they can affect the perception of sound, they do not alter the fundamental harmonic structure of the source. If you begin with a room or listening space with poor acoustics, treating the room will, of course, lead to a dramatic improvement in overall sound characteristics. However, this does not justify the misleading claim that room acoustics are the more dominant factor in timbre accuracy or shaping.  That is why a lot of audiophiles continuously roll the tubes, change/upgrade DAC (r2r, hybrid), preamp, etc. 

Overlooked. Options you didn't know about when you made a move. 

I used to work for a billionaire. All he wanted was knowledge. His options.

He got fed up with consumer audio and got three bids from pro audio contractors.