Summary: Disclaimer: My opinions are just my own. They do seem to be in contrast to some others' experiences, but we all have different preferences.
I heard great things about this headphone, and really wanted to like it. I can see why they are popular, and they indeed are fun. However, I'm a treble-head, and as one who was spoiled by the beyerdynamic DT880's, I hated them.
(TL;DR: I bought these new from Headroom.
Pros: Excellent bass, great impact and body, surprisingly comfortable for large noggins.
Cons: Lack of treble resolution, a bit of ringing, some quality control issues, heavy, hot.