Sound Quality > Build Quality > Looks
But I feel that what you mostly want to know is what in important in sound quality, in order, here's my ranking
- details, ie how the the headphones handles attacks and decays, the timbre of the instruments, unbloated bass, non confusing treble, how easy it is to distinguish instruments and musicians.
- sound signature, as long as it's not to extreme, I can like treble heavy, bass heavy (but non bloated), V shaped, but I have a preference for neutral. It is by far the easiest thing to correct with a parametric EQ, sound sig does also affect timbre though.
- soundstage, to me the best 'headstage' sounds artificial compared to speakers, even unmounting the bowls on my headphones and holding them in from of me seem more realistic. So I just make do, I'm kind of resigned, I mostly judge by how accurately I can place the musicians in my headstage.