This spring, I built a new Roon server based on their Roon ROCK software running on a NUC in a fanless case. It's great that they offer this software for no charge (once you have Roon), making it possible to build a high quality music server with linear power supply for under $1K.
I have found more great music in the last two years using Roon than I found in the previous 20. The sound quality is excellent, and the built in DSP functionality provides a lot of flexibility.
I also really like being able to control multiple zones around my house and be able to sync. While this is certainly possible with Sonos or BlueSound, devices that use Sonos or Bluesound don't have anywhere near the sound quality that is available with Roon devices.