I agree with you but I think that @litemotiv has a very good point: I update my software components (MinimServer, MPD, upmpdcli, the OS) on a regular basis. I do not expect such updates to have any impact on the sound quality of my system (although they might) and, indeed, I have never noticed any difference. I find it puzzling that Naim is unable to release a firmware upgrade for their streamers that fixes software errors without having any impact on the sound quality. But this is what Naim has communicated and hence users of Naim streamers are expecting firmware upgrades to have some impacts on the sound quality, for the good or for the worse. It is impossible to know how users would have judged the latest firmware upgrades if Naim had not stressed the fact that it is impossible to change the firmware without impacting the sound quality. We are finally replacing and upgrading systems that could potentially have a more or less direct impact on the sound quality of our systems all the time when we change bulbs, TV sets, computers, routers, internet providers, etc. But we typically go through these changes without trying to spot their impact on the sound quality of our systems because we assume, perhaps falsely, that they have none.
No mate, you have that backwards.
What you hear before s change is what you hear.
If there’s differences after the change, you’ll hear those subsequent differences.
What you’re suggesting is that it’s possible to experience something before it’s happened.
Indeed & agreed. A point to note, I went to bed extremely early last night. I felt wiped out. I had my COVID vaccination on Thursday, and whilst I had no effects from it I guess more work has worn me out I had many hours sleep. Today I feel like a new man, and currently listening to Royhead. .sorry I meant Radiohead on Quboz it sounds darn fine.
A thought: since the update of the system involves a complete restart/reboot of the system an all (sub)components: any chance, just the reset/reboot might have a difference on the state / SQ output? (Changed electrical/electronic/„digital“ state of transformer, DAC, whatnot?)
It would be interesting, if the people noticing differences shutdown their system between firmware updates (so, what „uptime“ their systems have) and/or how it is with people who do not notice a difference. 
I was mainly describing a situation in which you have a more reliable baseline to compare changes to, in a practical sense this could obviously still be challenging. But if someone for instance has a secondary reference system, or keeps a daily logbook about the sound of their system, then this could potentially be easier to achieve.
Baseline → Changes → Objective comparison
One thing that would really interest me, is if someone on the forums who feels they can reliably hear changes between firmware try this out for a while. If indeed this works as described, then it should be consistent and repeatable.
Roughly like this:
Day 1: write down assessment of bass/treble reproduction, sound stage, sibilance, pacing etc. Describe certain aspects of the music that stand out in a positive or negative way. Write down grades for each aspect.
Day 2: repeat
Day 3: repeat
etc.
Each day the report should be similar as long as the same equipment and firmware is used.
Then when a new firmware arrives, some of those aspects should change, reliably and repeatably:
Day X (new firmware): specific changes should be heard, grading should change
Day X+1: same changes should be repeatable/consistent, as well as grading
Day X+2: etc.
If the listeners hearing is objective enough to reliably detect changes, then this pattern should be clear and reproducible.
If there’s interest for this we could make an online system available in which people could keep track of this and compare historical data.
The problem being that after a few days, the aspects and grades would not be evaluated anew on that day, but would be repeated by rote. Psychology & testing is such a hard problem.
What does ‘rote’ mean in this context, i’m not sure if i know this term?
Rote, it is remembering something rather than learning and understanding it. I remember that 5 x 6 = 30, I don’t work it out each time.
Wow, that “sounds” rather serious 
I’m sorry, but I believe I’m not that serious about hifi.
I have fun chatting on this forum, but my free time is dedicated either to outdoors/alpine sports (perfect snow today!) or listening to music.
I’m concerned about firmware updates because they impact how my music/system sounds, and I enjoy sharing my findings thereon.
The way I share my findings is entirely spontaneous and subjective.
I leave procedures and science at work.
(btw, no need to say I’m very much aware of the environmental variables impacting sound).
That’s really all.
Which is, of course, entirely fine. I cannot be bothered either. But we should recognize that without such rigor there is huge room for kidding ourselves. “I cannot be bothered to be rigorous, but I have complete faith in my subjective abilities” does not work; if it did, and rigor was avoidable, science would be so much easier.
Oh you crazy youngsters! I spend all my time attempting to stay alive. The music’s an utter balm. 
Did someone say that it sounds like they added Loudness to this latest firmware? Maybe because I think they increased the output by about 3dB. I know what number I play each song on, and now it seems I have to turn it down by 3. I don’t detect any loudness function, it’s just louder overall.
That’s the thing that hit me right away. Still evaluating with my bronze ears.
I’m glad you’ve noticed this because I have the same experience.
I thought it might have been my ageing hearing.
volume was definitely different for me. I had to turn it down approx 10 on the volume scale and was hating the new sound, the bass sounded far too overblown for me. I unplugged, left it overnight, then factory reset and the volume was back to how it was previously.
Definitely an increase in output volume, but no problem for me (Uniti Nova). I am really liking the tweaks that Naim have done, no factory reset for me. Enjoying the slightly greater depth exhibited on my Dynaudio Contour 20’s. Nice one Naim.
I’m very happy with the sound produced by installing the latest update.
I thought at first there was an increase in volume and have turned the control down a notch.
I now wonder if the volume has increased or whether the greater clarity produced by the update allows for lower volume settings.
Interesting, for me it’s the opposite, feels like the volume’s been lowered. I have a star.
No change in volume. Atom
I think its more dynamic and not about volume up or down .. thats the reason that everyone gets a different fillings in his own equipment
Say what?
I can’t hear you, I’m trying out 3.6!