I ordered this headset to go running / to the gym, and an MM500, including but heavier for the rest of the time. (My ears do not support in-ear). I ended up returning the MM500 and MM100 keep only the. His side is very good, restores all, even if it's less "studio" that encompasses (it does not isolate outside sounds), but it is mostly comfort that convinced me. The lightness is surprising (56g), to the point that I forgot the headphones on my ears after my first try. Side practice it is rather small, flexible thus flattens very well in my pocket, visually unobtrusive, and I sometimes wears several hours without any problem despite my glasses (unlike encompassing that still rely a little). In short, the favorite.