Had these a while back. I'm training intensly (crossfit), and used these til I just decided to give them away. Sound is 3.5/5, could be better but it's great for the price.
But it just won't stay in your ear, simply put.
If you jog happily on an afternoon, it'll do. But if you're pushing sleds and doing weighlifting or very intense workouts, it will fall off several times.