I read someone said IE8 will arrive it final state after almost 1500 hours running. I do not have 8, but 8 and 80 have the same driver, right? But what I experienced cx 980 is exactly the same case. At the beginning, the bass is dominant and the high are dark. Now, after >1000 running, the bass is pretty domestic and tight, and high is very bright, somehow a little bit sibilant. And the middle/voice is brought to front a lot. I cannot believe my ear at first. Use a metaphor, before, it's like a strong man, now it's like a beautiful lady! I like it so very much! IE80 is much better than 980 at beginning, I just wonder how it will become?
Anyway, can you briefly describe what your 80 sounds now?
I still feel mid bass bloat on deep vocal jazz but either it improved over time noticeable or I got used to it. For example Susan Wong, Emi Fujita... almost anything from any best female vocal collections still isn't the most pleasant thing to listen to with IE80 but they had improved I think over time. Highs are sparkly as always, and I don't listen to too much metal or something so they aren't sibilant anyways to me.
Best I can describe is like I listened through a barrel sound when I got them and now over long time it slowly transitioned into normal sound, with less rumble overall. But It might be I just got used to it and I assume it's most likely that is the case :) Anyways I'm pretty happy with them except that mid bass, but I don't mind that either when listening to most of my music, just when I go full deep vocal jazz or bass guitar like Marcus Miller.