The harshness wasn’t even offensive most of the time. I just noticed it. I was trying to learn why it would happen where the Zen had minimal issues (minimal but not zero). I was also trying to figure out what production changes went in at the end of last year. No luck so far.
To be honest, I think I have reached the point where diminishing returns aren’t worth the price. In the brief period I had them, they shot to the top of the list for over ears. While I would take them over the arya, largely for the bass response and slightly more engaging sound, they have the problem that my Dunu Zen beats them on both those fronts.
If not for the isolation issue, I likely would have kept them as a wonderful leaner and more open/airy sound compared to Zen. This use case required isolation. I may re-buy them if I am ever looking for a headphone that doesn’t need isolation. (Assuming I haven’t found something I like more)
One more thing: the he6se + appropriate amp may be a better buy for the same money. However, the he6se bass response is not as impactful. The sound signature is otherwise more to my liking. The XC beats it more on function by being usable on many amps (including portable). With the diablo out now, the he6se is tempting again.