Anyone listen to Zu Audio's Definition Mk3?

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?

No, they do well at normal listening levels as well. I too am in a condo, though Im itching for a single family home with a purpose built room, and most of my listening takes place at sane levels.

A few people have commented in this thread how the definitions come to life at lower volumes... do a little skimming, especially through 213cobras posts.