No matter what test CD you play, your exposure to the music on a variety of systems is what makes the difference. It's kinda like porn. It's a "I know it when I see it" kinda thing. The wider your exposure, the more certain you are of what you are hearing.
My pesonal judgements below are based on a couple of decades of listening through all differenet types of gear. Tubes, ribbons, OTL amps, Stax headphones, MC/MM carts, solid and stranded wire, big rooms, small rooms, etc, etc.....
The following (and many more) recordings have nuance that when done properly comes across immediately and unmistakably. As stated before, you know it when you see it!
Here's a couple of my favorites. All choosen for their ability to "connect" when reproduced correctly.
Rickie Lee Jones - 1st album on vinyl and Pirates on vinyl. (CD's no too bad)
Mighty Sam McClaine on Audioquest both CD and vinyl.
Sarah Vaughn - "How long has this been going on" on Pablo CD.
Lyle Lovett - "Joshua judges Ruth" on CD. (If your not there, you're dead)
Holly Cole - "Don't smoke in bed" on CD. How 'cliche, but when this one's done right you'll be moved to tears.
There's many more but my fingers are tired.
Listen, share and enjoy.
OTL