My favorite test track with the kuros is Attaboy from the Goat Rodeo Sessions with Yo-Yo Ma. There is just so much detail in the song and the Kuro renders it perfectly. Even my Shure 846s don't perform as well. The only complaint I have is that the Kuro is not an earphone that you can just relax with. It reminds me of the IE800 and Etys in the sense that it forces your mind to think about the music you are listening to. However, unlike the IE800 and Etys, it is very comfortable. It's proof that an IEM can be immersive without being fatiguing.
My other test track is Kanye's Black Skinhead. There are several portions where there are multiple voices singing the lines especially at the very beginning of the song. With most other IEMs, it seems like a single voice. I've only been able to catch the separation with the IE800, HD800, F111, and the Kuro. When I had the Kaede, the song was a little too bright for me to do anything other than wince :(
My take on the Kuro is that it is phenomenal in a quiet listening environment as it provides mediocre isolation. They definitely look and feel like boutique IEMs with minor imperfections unlike most other mass-produced headphones. However, they are a really unique experience.