Okay, reporting back as promised.. [no spoilers]
I'll post the subjective assessment I shared with Noah and Nick after a second listen at home through my "good 'phones", even though it didn't change the initial judgement I posted above-
I still prefer file 1. It has better sense of spatial clarity, separation of sources, and initial transient edges. File 2 is less 3-dimensional and more homogeneous. I confirmed this subjective assessment and preference through rapid A/B switching while listening critically, and also though more casual longer-term listening, the latter consisting of both focused listening as well as distracted "background music" listening. I end up with the same preference for file 1 in all cases. It's not earth-shattering, but a significant enough difference which I quickly became well-enough adapted to that I could pretty rapidly identify which was which correctly each time upon randomizing the stimulus. The more I listened the easier it became to confirm a preference for file 1.