I have Sonos in my house, a couple of the portable units, and a couple of the white boxes feeding some stereos. Plays music from my NAS, SiriusXM, Pandora, Spotify and local+internet radio.
While the wireless aspect, and the multitude of sources available, make this an easy to use unit, I don't think it really works that well for a critical use source. It will only play 16/44.1 files. Higher rez files are not played. The on board DAC is generic, and the SPDIF is pretty jittery. (one can get a modded one from Wyred4Sound with much improved SPDIF)
That being said, its absolutely wonderful for its designed purpose, music anywhere in your house, easy to use software, that is spouse friendly. I heartily recommend for "house music" or playing outside in the garage and or barbeque. If you are looking for a high end source for a headphone system, I would look elsewhere.