Not sure because I have never bought any blutooth headsets (other than the ones used on one ear for talking).
The problem is that they only last maybe 8 hours at most, and require recharging. I'm a person who will probably forget to charge the headphone. Also, it could run dead in the middle of a movie. It has also been difficult to find blutooth ones that are in two pieces (one for each ear) so I can share an ear piece if I'm with a friend. I did find one online, but it required a cord between the two pieces. Thats useless, because If I wanted a cord I wouldn't get a wireless headset.
For those reasons, I think I can deal with the minor inconvenience of having a cord headset (for media, like videos and music) if it means I won't have to worry about charging or if it will run dead on me.
The only problem is if you plan on sitting far away from the device (limited range with headset cords) but I don't think such a situation is likely. If I was at home I would rather use a television. If I'm on the move I can just set it in my lap or hold it etc...
So when you really think about it, blutooth headsets are not as convenient as they seem, for the purpose of watching media on your phone.
Now, using a blutooth compatible car stereo system is obviously very convenient and useful
