So, I recently picked up a D8k Pro and also tried it with the Washi paper pads... it's very, very good in terms of its technicalities and presentation -- just like many of the TOTL planars. However, I can't get past this sort of "shimmer" or "tizziness" that every single planar I've tried has imparted on the presentation, including the Caldera. It's probably just a matter of acclimation, but then I go back to the Atrium Closed, Z1R, etc., and it just sounds "right" (frequency response aside).
My hunch that I'm just someone who prefers dynamic drivers is starting to really solidify. As a result, the VO is probably the single best open-back I've heard to date.
A bummer, really, considering all the modern R&D takes place in planar and electrostatics since dynamic drivers are considered a "solved problem" in 2025. I guess that's good news for my wallet, though. lol