Got the Oppo CD player. Both it, and the Aries Mini, have coax outputs. So I can hook them both up to my DAC, and continue a fair apples-to-apples comparison of Roon music over the Mini vs. the original CD. But I’m not. I don’t see the point anymore, because…
As everyone knows, Auralic recently upgraded the Aries line to being RoonReady EXCEPT they excluded the Mini. Frustrated at not being able to listen for the improvements RAAT might bring, I purchased a SonicOrbiter SE (SOSE). It’s nice, inexpensive little RoonReady network endpoint, with linear power supply and a USB connection. I should mention that I purchased a new USB cable, because when I hooked the SOSE - with the new cable - up to my wired network and my DAC, I started playing digital music from Roon that sounded better than ANY digital music has ever sounded on my system. Really. Hi-res content - in particular - sounds glorious. 
So, with the Aries Mini being restricted to AirPlay emulation if I want to play tunes from Roon, I honestly don’t see the point of using it. When (if?) Auralic finally upgrades the Mini to being RoonReady, then it might be time to compare the Mini’s sound to the SonicOrbiter SE. I’ll make that decision when (if) Auralic makes that upgrade. But in the interim, I’m retiring the Aries Mini, and enjoying the awesome sound that Roon (and the SOSE) is producing now.