Well, my Blackwood Auteur has been playing for 100+ hours, and have gotten 15+ hours of head time. I've been doing the 'burn-in' thing ... just because.
I haven't really heard any significant changes, or maybe they just crept up on me unnoticed. In any case, I'm pretty sure that at least my brain is fully burned in.
I posted a shot of my 'Wall of Fame' here:
https://www.head-fi.org/threads/zmf-auteur-thread.862918/page-60#post-14094931
From left to right, Utopia, HEKv2, EFO, Blackwood Auteur. I also jut got in a used Bryston BHA-1, which I purchased in an effort to 'soften' the Utopia listening experience. To be clear, I love the Utopia (actually all these cans). But I find they can be fatiguing -- just too much detail.
I had previously tried a Denafrips Ares, which did help, but at the cost of too much lost detail. Bryston does help the Utopia.
All that said, my ears hear the Auteur to be very close to the Utopia. Similar detail, dynamics/impact, soundstage and tonality. However, I don't hear the Auteur as fatiguing. In fact, while I prefer the Utopia with the Bryston amp, I slightly prefer the Auteur with my Violectric v280, although it's not a big difference.
Besides the fatigue thing, I'm finding one other reason to prefer the Auteur to the Utopia -- tonality. The treble on the Utopia can be too forward. There are a few songs where it's really striking. Some instrument (say brush on hi-hat) is too accentuated. It's great that the information/detail is there, but it shouldn't dominate the sound. It's like a dish where the cook used too much of one spice and it ends up dominating the flavor. I noticed this on a couple of songs where my first reaction was '...less bass?' but then I realized the bass was there, but it was being 'masked' by the high frequency information. It's not extreme, and not very noticeable on many songs, but it's there. An example is 'Beyond my Wildest Dreams' from Mark Knofler/EmmyLou Harris's 'All the Roadrunning'. There's some plucked guitar notes behind the voices in the second and third choruses. On other headphones those notes are just an accent. On my Utopia, they're front and center -- emphasized too much.
I just don't get that from the Auteur. Tonal balance seems right on the money. Bass is very well defined and fast/impactful without being thick or bloaty. Highs are present and detailed, but don't dominate. Mids are just beautiful. Overall, these cans are both wonderfully detailed, yet balanced and musical.
In fact, I'm going to summarize by repeating my earlier statement -- these are my 'Goldilocks' headphones -- just right.
HEK/EFO are close to each other, and quite different from Utopia/Auteur. More laid back, less detail, bigger, more open, less precise sound stage.
BTW, all listening has been PC ==> Eitr ==> EVS-modded Sonica DAC ==> Violectric v280/Bryston BHA-1. All analog connections are balanced. Using ZMF OCC balanced cable to Auteur, balanced OCC copper cable from LQI cables to Utopia.