Comfort is fantastic. I am not sure I can switch from a microdriver IEM after using Forza Metallo Wireless and the Aurisonics Rockets for so long. They both just disappear into your ears and you can just forget about them no matter what. They are small enough for motorcycle helmet or for laying down on a pillow. It is just fantastic. Though the sports fins can irritate my ears after a while, but I would only use them when I'm running to keep the IEMs from moving.