Where HFP and HSP send audio to and from both devices, A2DP is a one-way street, but the audio quality has the potential to be much higher. A2DP is well-suited to wireless audio transmissions between an MP3 player and a Bluetooth-enabled stereo.
Innen, szóval ha csak a2dp-t tud, akkor "gyarilag" ennyi.
Azt nem tudom hogy "megosztható"-e a hangszóró/mikrofon droidon, szerintem nem.