Check out this informative video from expert Hans Beekhuyzen thoroughly explaining what makes the ZENith a class leading Music Server.
June 2019 I reviewed the Innuos Zen MK3 music server and was rather charmed by it. The ZENith MK3 on review here is the 'high-spec' version of the Zen. And like the Zen MK3 it can work with Squeezebox, Sonos, UPnP, as a Roon Endpoint and even as Roon server.