(I don't know how to reply directly to a comment, but THIS is what I was talking about)... From dinosore:
Be aware that when you use AirPlay2 on an iPhone or iPad, the Apple Music app will down-sample the stream to a very lossy 256kbps (versus 1,411 kbps for 16/44.1 CD quality).
I suppose I wasn't clear... this would be typically my wife playing music from her phone, or me playing music (from my phone) when we are doing chores (not necessarily in the room with the stereo). Actually, we live in NYC and don't have a "listening room" like many of the folks around here (I can't imagine what that would be like).
So, it seems that the DAC (either Bluesound or external) isn't going to make much of a difference since the Apple Music app will be killing the SQ anyway.
Thanks for the responses!