I know I could never find one that would allow me to hear the person calling me.
If your hearing is as bad as mine, bluetooth headsets for the cell phone were the white whale of telephony. I loved the concept - I can keep working with both hands, climbing the ladders, squirming through the attic and still not miss that 'important' call from the boss wanting to know what the hold up was (you know, besides his 47 calls).
As part of our Christmas, the wife and I went down to the Verizon store and re-did our deal to get some different phones.
She HAD to have an iPhone (5C) and I got a Droid Mini. Which means I FINALLY have a phone that fits in a pouch. My old Revolution with its protective case was a monster. The mini fits even with its Otter Box on.
But I digress... SO I saw these headphones that looked intriguing, tried 'em out and bought 'em. Been loving them ever since. For the first time I'm using my phone as a music player and I can do a hands free call while actually hearing what the other person is saying.
It may have more to do with the phone and the three year gap in technology, but with the revolution voice calls were more or less just spinning the contacts wheel - but now I can make 'em first time, every time (even working 95% with text and notepad) through this device. Answering calls is super easy.
In case you are missing it - I endorse these. They are light enough I don't even know I'm wearing them. The only frustration I have so far is that when wearing a jacket the ear bud (I usually only have one in on the work site or driving) I'm not using gets knocked out of its magnetic cradle and I just know I'm gonna end up ripping it out.