Summary: The sound is like any other Bluetooth headset. It may feel like the bass is better because it's an in-ear. The box itself suggests that when you are running outside, you should have the mp3/phone on an arm band strapped on the right arm.
Pros: It offers you mobility when you're exercising, small compact, barely know it's there. The in ear fit device (whatever it is called) really hugs your ear and prevents the headset from getting loose.
Cons: Short connectivity range. If you are Iphone user, you may initially find the control bad. Mic easily picks up the background noise and muffles your voice.