I like using Bluetooth headsets for my cellphone, mostly because I like having my hands free. Also, I'm hard on gear. Several years ago I used a Jabra JX-10 which weighed almost nothing and was tiny. I briefly used a Jawbone in an early model, then (due to time pressure and limited selection where I was at) I switched to a Bang & Olufsen Headset 2. Great sound quality and battery life, it looked awesome and I tended to get unsolicited compliments from strangers on its style. That one died after three years so I replaced it with another one a bit over a year ago.
This weekend the B&O speaker stopped working: the controls worked, the microphone worked, I could use voice control and operate the phone hands-free, but I could hear nothing. Clearly a mechanical failure of the speaker. So back out shopping, and the best thing in the store I found was the new Jawbone Era model: smaller than my old one even though it is the large model now, better battery life and faster recharge time (plus standard USB-miniUSB cable versus the proprietary charging shrine of the B&O), as good sound quality, and even on a single weekend's experience a much better UI than the B&O. In addition the full retail of the Era is just barely over half the best possible cost of the B&O - I've liked the B&O but it's so pricy I can't recommend it as cost-effective. I'm going to give the Jawbone a try for a week or so under varying conditions and if it doesn't fall off my head or I don't get sound quality complaints during my conversations I'll probably keep it: if the Jawbone fails on either of those points it's going to be right back to the Bang & Olufsen.