Of course since most of the issues seem to come from things like interaction with cars, and GPS tends to quickly drain battery thus strongly encouraging using a charger, and therefore lack of a headphone jack makes getting audio in the car much more difficult... well, that "as long as you are not charging" is a pretty big negative. And that's ignoring all the various issues Bluetooth has, like some apps (eg Waze) utterly failing to output sound over Bluetooth most of the time.
Is it really common to use headphones in the car, though? The last few cars I've owned, I plugged my phone into the radio with USB and it both charged the phone and played music as well.
Lots of cars don't support transfer of audio via USB but do have an AUX socket.
I think OP was talking about people plugging between the headphone socket of their phone and the AUX input of the car stereo - not wearing headphones in the car.
It is _very_ common to charge the phone and listen to the music at the same time. Maybe only for me ... But I won't ever buy these 1-port-for-everything devices.
