I just received these from a member of the forums second hand (so they've been burned in apparently) and they are very sibilant. I am needing to EQ them twice to get them tame, and then they sound wonderful.
In actuality, they sound very similar to the 590s save the fact they are closed. Since EQing the 590s, I have learned to like the sound much more, as it tames the highs a lot.
The bass is huge, absolutely mountain crushing when equipped with the right song. Listen to Incubus - "Deep Inside" or "Idiot Box" and feel to the bass on these babies. In reality, I'm a little disappointed, but they sound too good for me to complain.
Anyway, they are closed and block a hell of a lot of sound, which I like. Unfortunately, they make me look like an idiot, so taking them to school is out of the question.
So, I like them.
Yea.