In my opinion breakin is real. I have spent years tracking and documenting my system as I introduce changes (tweaks) into the system, to find out what happens.
Why it is so, I don't have a convincing reason, other than I hear the sonic information morph and change as more hours accrue. And it usually means (if the current experiment is 'successful') that these changes improve the experience. But this progression does not mean it only gets better all the time. No, no.
And while I could come up with convincing (at least to me, but I'm easy…

) reasons as to WHY all of this happens, I doubt it would stand the test of time. Simply put, we don't have enough of a grasp of what is happening in total, for me to be able to piece a cogent explanation together, that truly reflects what is going on.
I have been tracking these changes in a log for years now (34 pages so far) and while the patterns shift about a bit, it is not uncommon to take many hundreds of hours before the sound 'matures' and fully blossoms, and the most impressive of the sonic characteristics present themselves, and stick around.
These characteristics are common enough that they repeat themselves as changes to the entire system are made and more new characteristics are added to the list as they emerge.
Right now with 260+hrs on The Rok, the sound is really starting to focus up rather well.
I'm hearing similar sonic aspects to what my Mojo has.
And they only manifested, when I was running the Mojo, after other tweaks were performed and those new (at the time) aspects became apparent.
And this pattern begins again during the next experiment, as most of the 'advanced' desirable sonic improvements go away and then come back as 'enough' hours are once again accrued.
Sometimes they come back only to go away again, and then to return etc., until it all blossoms.
This is a repeating pattern I've seen over the years I have been tracking this.
So right now The Rok is heading into the rarefied heights of sonic tweakdom.
This pleases me a great deal, because I haven't even started experimenting with further tweaks, and The Rok is already headed into the very domain I seek. :thumb
But The Rok needs more hours yet to fully 'stabilize', before I experiment with it, like I did with my Mojo.
I call this ability to be 'improved' as scalability, and when the whole system scales together well, it usually results in sonic nuances and a degree of involvement in the music which is most gratifying.
JJ