Had a K702 years ago and hated it. Some people complain that it has a plasticky treble, but I would have said metallic; I really just didn't find it musical at all. Maybe I've just got funny ears.
There is, indeed, a disagreement within the community about K70x's treble. I find it bright and crisp, so I've sometimes used it to wake myself up. Overall, the detail is among the best, but the instruments sometimes sound too far apart. I simply don't love them, and that might induce me to sell them.