I use several different bluetooth stereo headsets. they do serve a purpose. I especially love them when I'm working out in the gym. I leave my phone in my bag which is next to the machine I'm working out on or in my pocket. I also do work that requires my hands in a noisy environment. Having a cable that runs from my headset to my phone was a hazard where I used to work so the stereo headsets were a must.
I will say however that bluetooth is a POWER HOG!!! When I have it on all day I get maybe 6 hours of use if I'm lucky. One day I switched to normal headset via my adapter and got 14 hours on a single charge still playing music and audio books all day. In addition to the power issue. Now I have to charge two devices and hope that one doesn't run out of charge before the other.
So for now I use the right headset for the right circumstances, but I have to tell you that switching is wearing on me and I hate leaving the house and not having the right headset with me or having to carry both with a full charge and the wired ones just in case the charge runs out.
Bottom line is that bluetooth is a significant power drain on the phones especially if you are going to use it in stereo mode for an extended period of time. Its why Apple didn't implement bluetooth stereo mode on their products right out of the gate. They wanted to manage battery life opinion and knew that their base of users "not the brightest bunch of people in my opinion" would use bluetooth stereo right out of the box bypassing the wired headset. Now they have all of their users accustomed to wired communications and its an option for those who might want it to get a stereo bluetooth headset. Pretty briliant on Apples part to manage their user base.
There. Now I've put in My 2 cents. hope this helps someone.