Gotta say the highs got really better with burn in (at least IMO). My problem with bass imalance is slightly there, but is that subtle that Im starting to get along with it. I dont feel like returning them, I already had some problems with my last cans (Beyer COPs) and I want to keep those, Im tired of returning phones.
Only negative thing is that the bass got a little weaker with burn in IMO. But is still enough. They're not basshead phones for sure, but will be more than enough for non-basshead people. Im loving those for melodic Trance music.
What's funny is that I haven't looked at this thread in well over a year (or so it seems).
And it's really great to see that these are still popular and appreciated.
As for your experiences... Yes! That's exactly what I, and many others, have experienced. The 'lessening' of the Bass actually seemed to me to be a 'tightening'. Less sloppy and boomy then they were straight out of the box. I'm grateful that they retained their punch.
And yes, the highs get less 'metalic' (as some called it) with burn-in.
These are great all-rounders. I've had mine for years, and they serve me very well.