I have the m6's, and they are FANTASTIC! Just about the only headphones that can handle an intense workout, cardio, jogging, pliometrics, yoga, and racquetball without slipping out.
The wire part of the cord you actually wrap OVER your ear, the best way to describe it is the old wire trash bag cable ties.
Even through sweat, jumps, and whatever I've tried to do to dislodge these dern things, they don't budge until I pull them out. Only headphones I've found that can handle it all.
Sound quality? fantastic. I purchased them after reading reviews of them being too "bassey" for some people, and thought "yeah, sounds perfect for me!" The sealed ear canal really helps the bass develop and "kick" in your ear.
Only warning? these are sealed ear headphones, and go in pretty deep into your ear canal, deeper than many other "ear buds" I know a few friends of mine find them uncomfortable when trying them on.