Three days into the burn-in of my ZS7 and yes ... that piercing shrillness is almost gone, just a few weaker treble peaks left here and there, more spatial precision throughout the spectrum (less halos) and I can finally really enjoy these IEMs. Now that everything sounds far more relaxed I replaced the braided 8-core KZ cable with the grayish 8-core Kinboofi that doesn't seem to work that well with the ZS6, at least when it comes to clarity. I'm still amazed by the perceptual transparency I get from my older, grey ZS6 with this KZ cable (on my standard rig with good recordings); any of the other cables I've tried literally don't cut it for me. On the ZS7 it seems the other way around albeit less distinctive than on the 6s - slightly better clarity with the Kinboofi compared to the KZ cable. Anyway, after some more days on my ears and the burn-in rig (@ much higher volumes) this combo could turn into my new #1 for all sorts of house, UK garage and hip hop vibes (bass, bass, bass) but jazz doesn't sound too bad either through those guys.