This unit is a bit of a chameleon. If you try to use XLR to RCA adapters, don't expect much. In fact, I bet you won't like it. The AIR wireless playback is good - for wireless playback. The USB is outstanding. The phono stage is outstanding. The other digital inputs and analog inputs are good. But the meat and potatoes of this baby is in the USB and it's excellent phono stage.
I was unable to test the Ethernet connection, but Devialet notes that even the wifi is better.
I recommend the following connections - Ethernet (not wireless) to Computer, Computer USB to Devialet. Connecting my MacBook Pro to my network wirelessly, and then from the MBP to the Devialet via USB was a little choppy. Using Ethernet was a better way to go. The phono is a straight forward connection.
Describing its sound, I would say it definitely resembles Class AB with a certain degree of sweetness. Using USB and phono, there aren't any typical rough edges that we associate with Class-D.
If you like your music very clean and clear, with a hint of sweetness, and you plan to use USB and/or Phono, I think you will be very happy with the Devialet.