To be honest, the treble doesn't bother me anymore, they really settled down after a week, I am just hoping that Fostex purposely handicapped TH600 by omitting this stuffing, technically it should kill bouncing off the enclosure reflections and clear them up a bit, but we'll see, fiberloft is in a mail.
The treble has very impressive resolution and detail as I am now noticing all the staticy treble distortions on some music files that were much less noticeable before...
Compared to my other cans the same distortions were more hidden and I previously thought were just the cans treble, but can now more easily tell its the recordings.
Regardless the music still sounds better because of overall musical presentation is just a constant lively wow factor...
Edit I also noticing the "brain burn" effect as now my audio technica esw11 sounds like too much midrange... Noooo lol