How loud you listen is a factor as well imo. The only time treble is an issue with me is when I crank them right up.. My HD600's at the same volume aren't as fiery. At my normal volume which admittedly is probably quite low, I've never had any issue with the treble no matter what recording (even Miles trumpet).
I recently did a little comparison between the hd600's and 800's to see at what level distortion would start to creep in or the sound would deteriorate. Unfortunately my ears can't handle the kind of volume needed for this haha. But what I did discover, was that the HD800's are quite a bit more sensitive. I could get the volume a lot louder with the 600's before the treble got really annoying.
I also had the sense to try 'bass only' music and so using a double bass solo I was able to crank both of them right up. But the clicks, plicks and slaps soon became very tiring with the hd800's as they pronounced the treble over the bass more so than the 600's.
Anyhows, I couldn't hear any distortions on either, but the 800's are really quite amazing, boy can these cats get loud! - the control and resolution didn't seem to change at all, even the sub bass stayed tight. The 600's blurred a little and the bass had more bloom at super high volume. The bass on the hd600's is not on par with the HD800's anyway, but they do have a nice controlled punch to them, though it doesn't extend very low in comparison.
So that was it... HD800's stayed the same at stupid volume. The HD600's didn't seem to distort, but did not show the same control as they do at lower volumes.
This was done with a Sansui 551 which is very loud (louder than any headphone amp). This amp is loud at 8 oclock - I cranked it up to 11-12 for the test. I wouldn't recommend anyone doing this simply for your hearing. I played in bands for 20 year so I'm used to loud and I only did it for very short periods.
A pointless test, but a fun one