@tim
It sounds quite good coming over Bluetooth 4.0, but thank goodness there's a plethora of other inputs available.There was a marked improvement when I hooked these up to my Matrix DAC via RCA.
The nice thing is that you've got a lot of utility with these. Friend comes over and she wants to put on something for casual listening? A couple clicks and her spotify is filling the room through bluetooth. Time for some focused listening? Swap them over to RCA, Optical, or 3.5mm input with one button press and you're ready to hear the finer points of Beethoven's 5th.
All about the utility my man : )