[MousoMachineGun]

Just got mine too!

Here is my first impressions, hooked up with RME ADI-2/4PROSE, and SRM-006tA:
I overall agree with @mtthefirst impressions above. So just to add a few things, I posted the PEQ adjustment below to illustrate better. (Note: Tuned to my hrtf. I don't have any measurement rig so I do this by ear. And Harman is bright to my ears just to make my bias clear)

-Bass: just as mentioned, bass is light in quantity but it does exist and the quality is there , so I just added about 4dB total in subbass and a +1.5dB low shelf midbass

- Mids: there is a peak at around 7kHz that makes vocals sound unnatural, so I applied a slight dip here.

-Highs: there is no sibilance, but above 12kHz it seems to be boosted a bit much, so I applied low shelf here. I suspect burn-in or amp synergy issues here. Because I didn't recall hearing this in the demos with the new set amp.
UPDATE: The peaks seem to have gone away after I ran it playing music overnight. Also seems to sound smoother now. I'll need to listen further, but very happy with where this is heading.

Technicalities: I think detail retrieval is about on par with the L300LTD I had back then by memory. Ofc this is not at all x9000 level and I think L700mk2 is still a bit more resolving.
Soundstage is narrow, kinda like og L300.

Again this is early first impressions, I'll update as I go along. Cheers!