Robust zone audio sync would be a fantastic addition for MC23.
I was at Best Buy the other day, Sonos is at the front of the store. Sonos systems are really expensive, but people buy them. I think syncronized audio is becoming a normal feature for multi zone audio.
Airplay systems can be a cheaper alternative, but requires some hardware and software fiddling to set up with JRiver (search the forum for Hilton's Airplay guide, for example.)
I think Airplay works by running a millisecond audio clock on each playing zone, making adjustments automatically as zones drift. Airplay sync is solid and the code is out there...I've seen several Linux and Python versions.
Would a JRiver alternative be easy to implement? Or is audio sync a resource drain and development black hole? It sure would complete the picture for whole home audio integration.