I can't say. I have a decently sized head, a little above average, and the leather headband makes it MUCH more comfortable to wear.
I've been doing some comparitive listening between the earlier revision and the newest revision - Dan, is there anything to explain these being slightly brighter?
I am noticing some sibilance on certain songs (One More Time by Daft Punk ("one tsime we're gonna sselebrate (oh yeah) don't sstop the dantssing"))
However, It's much better as far as sibilance than my HD598, still. At its worst it's just as good, so I'm not that peeved. The older pair seems to be just as sibilant (as the new revision), maybe a LITTLE BIT less. I can't really tell.
Could you try this possibly, if you have time:
Do a slow manual sweep of 4kHz ~ 20kHz, take notes of how the frequency response curve perceived is across that range
This way we could have a better glimpse of approximately how the treble region "looks" like with them.