Ryan,
The advantage of a BT headset is apparent when you want to Bluetooth the audio from the Audio panel to a Bluetooth capable camera like the Garmin Virb Ultra 30. That way you can record cockpit audio in real time onto the video camera while still listening to music from your phone/IPad via your Bluetooth headset. The Garmin GMA 245 audio panel has Bluetooth capability but can only interface with one device at a time.
I can listen to music from my IPhone on my Bluetooth AKG AV100 headset while recording audio from the GMA 245 to a Virb camera. I can use a camera in the cockpit set up as the “Main” connected via a cord to the headset jack for audio and another externally mounted Virb set up as the “Extended” camera that is controlled by the “Main”. Interesting setup is that you can control both cameras from the Aera 660 GPS sub menu using the built in sensor or via WIFI, you just have to remember to turn the camera on so you can start/stop recording from the cockpit. The GMA audio panel Bluetooth signal is strong enough to broadcast all the way out to either wingtip. I did try it under the wing and fuselage but the audio and the start/stop signals are blocked by the aircraft structures.
And like Todd said, if you have two Bluetooth headsets each person can listen to their own music.