I was reading your post immediate;y after reading the ones about the little single to double post adapters. I skipped right over your reference to the AirFly Bluetooth adapter and responded assuming you were referring to the other adapters.

Personally I don't fly with a lot of expensive gear. I have a decent tablet with a .5 TB MicroSD card full of video and audio content (and a 3.5mm audio port). If I want to view the airline's entertainment content, I use one of those $2.00 adapters for that purpose and avoid using the headphones provided if at all possible.