Against:
The angular shape at the base of the helmet will not be suitable to everyone, can be uncomfortable.
The flat cable, the idea is good, but in practice it transmits vibrations lot.
Therefore obliged to trap it between two buttons of the shirt not to have the impression of having a stethoscope in his ears.
Not to mention it has more wind resistance than a breeze and makes him flying if it is not hooked.
Conclusion: Ideal for home, where if you do not move much. Avoid jogging.