Anyone listen to Zu Audio's Definition Mk3?

Hmm, expensive tubes, and just when you thought you could get off the constant, pricey, upgrade path...
Back to the matter at hand, the Def4s. These really are chameleon like, and require a LOT more work than the 2s to get right, but BOY is it all worth it when they're singing. My main downside is that I'm struggling to get my analogue to sound of it's best. My new tt with the Def2s roundly trounced my digital, but with the 4s I can't quite dial analogue in right yet, and my EMM Labs cd is in pole position, sounding just great. I'm finding that with the quantum leap in transparency possibly my cart or phono stage loading is awry, but am sure I will get there. I'm very tempted to audition the Soundsmith Straingauge cart, possibly the fastest most transparent cart on the planet, which I think may well complement the 4s nicely.
These babies are a lot more sensitive to set up - I'm finding they really like a lot of toe in, and the bass adjustments sound great with factory presets. IMHO don't be tempted to boost the bass too much, otherwise a real disconnect from the FRDs will result.
I'm happy to say I'm "getting" the treble now. Initially I felt it was still too reticent, like the 2s, but as I've got used to them, the HFs are really opening up. I love how the treble really is a natural extension from the FRDs and not spotlit at all. This is all adding to the sense of realism across the board.
My only slight feeling of disapointment is that they sound a little more subdued than the 2s at lower volumes, puzzling since the efficiency rating is still 100db+. I am finding the need to turn the volume up a little more, which is an issue during late night sessions. It may be that the gains in transparency and detail is slightly offset by a decrease in density.
Will post further as get to know them better.

The Def 4s evolve over months, not days or weeks. It is necessary to be patient.

I've noticed that slow break in with all Zu speakers....especially if they are played at low to moderate volumes?

Yes, I have to agree with the above. I've never owned zu's that didn't evolve slowly over months. The good news is that the Def 4s sound pretty decent out of the box (unlike my previous Defs), but they will go from good to great to awesome over the course of time. Play them at louder volumes when you are away if you can. I put on raucous music while I was at work and this has sped up the break in. And while you don't have to crank them as loud as previous Defs, they still benefit tremendously by sustained, louder than normal volumes. I don't think chamber music at polite volumes will ever cut it.

These have been on my list as audition speakers when replacement time comes. But one of the things I’m taking away from the above posts is that a primary virtue of these speakers is that they play loud. Since I live in a condo and never try to listen at live levels, would it be advisable for me to remove these from my list?