Sonos can be very good. You need wifi or Ethernet to make it fly. Just hang a Sonos Bridge ($50) off your router and get a Connect unit for $350. At that point, you can use the solid DAC in the Connect, or go dig out to the DAC of your choice. Add an amp and speakers (as much or little as you want to spend) and you're good to go.
Control the system via a free iPad or iPhone app.
You can stream from a remote networked library on hard disk or from an on-line service, and/or hang a cd player off the connect as an in-room source.
SQ can be very good (especially with an external DAC) and is mostly limited by the quality of the DAC/amp/speaker you've chosen. Moreover, the system can be expanded to as many rooms as you like. The downside is no ability to handle HD files and a bill that mounts quickly as you add rooms. Notwithstanding cost, I was an early adopter of the system and I'm now at 11 (I believe) rooms on the system.
Good luck
Marty