It so smooth. After spending quite a lot of time listening to these phones (Ive tried both the 600 ohm and the 250 ohm versions) I now feel qualified to write a fair appraisal of my listening experience with them. Its not a big deal and the slipper is worth it! Especially considering the price range. Robusto. They seem fragile and a little "loose" in their construction. Cons:- Handles are fragile. I’m a size 8 so I ordered the M (7/8) and there’s about an inch of extra room at the back so it could probably fit up to a size 8. Im an 8-1/2 wide, tried size 8, was too short a little narrow. Nach einer Woche wollte ich die Badeschuhe wieder anziehen, doch sie passen nicht mehr!