Thanks again
@BDWoody . But at least you agree I should be able to tell the difference between playing my FLAC 16/44 files over ROON--Airplay vs just continuing to use iTunes MusicMatch and my underlying 44/320 kbps MP3s over Airplay to the same AX2080 setup?
Honestly...I doubt it, but that doesn't mean I wouldn't do it myself. The Roon-CCA combo is just so convenient. You can also add more and sync them through Roon, which you may already know since you have one. CCA optical in to your Amp, Roon-CCA... That's what I'd go with, but again, it would be for convenience, not sound quality.
There are sites where you can test your ability to discern between varying sample rates... Most don't get beyond 192k, or maybe 320k, but beyond that...best of luck.
Have someone switch between them without you knowing which is which after turning the volume down between switching...after you get your Roon trial...and see (hear?) for yourself... Would be interesting.