The black dot now: fragility.
This headset is very fragile. After 4 months, the left earpiece passed away. As long as you read other reviews you will see I am not the first to make the observation. Amazon sent me back to that AKG referred me to an authorized shop. Valid warranty, free exchange. Great!
Maintenent I hope he will also hold long as possible.
Oh, I almost forget that fragility relates unfortunately also the cables extremely fine for a helmet that is to be nomadic (note the very strong hard case molded to receive the folded helmet).