Its side, pretty good, despite a little lack of power of the medium side (too used to my Sennheiser!) But not as much as I thought given the other reviews.
Very ergonomic. The shape of the headphones themselves may seem a little odd (in the ear part offset from the rest) but they hold well in the ears. In addition, given the 4 different sizes of rubber tips, everyone can find happiness.
The wire does not make knots and are possible to shorten it with a small piece of plastic provided for those who wish.
We'll see how long they survive!