I wouldn't recommend a DDC unless you have your room dialed in meticulously, it is much more cost effective to use room treatments and DSP before getting a DDC.
Does a DDC make SQ of all basic streamer roughly equal?
Vinshine Audio has a YouTube video of a Lumin streamer and makes the point that a DDC is less critical with a good streamer such as the Lumin vs something like the BlueSound node.
Ignoring the higher end streamers of Lumin + Auralic, do you think a Denafrips Hermes DDC attached to any of the "entry level" streams effectively narrows the sound quality gap across models like BlueSound Node, Wiim Pro, Innous Mini, EverSolo, Matrix, etc, etc.
I understand a DDC can't fix everything, but does it get you close enough SQ wise, that you can simply pick your streamer based off your preferred user experience of the software? I do realize this is subjective.
I also wonder if that same Hermes DDC can elevate any regular CD player or BluRay player to the point where a dedicated transport (outside of the high end models like Jay's Audio) also won't had benefit to your CD playback.