First off: the headset is awesome! It's incredibly light and the ear clip is barely noticeable so the comfort factor is higher than expected. Note: I normally hate those "put into your ear canal" type of devices because my ears seem to defy all standards and usually they start to hurt badly after only a few minutes of wearing such devices. Not with this little gem: it came with several sized clips and ear-plug thingies so there should be plenty for everyone.
The sound quality is very much OK - not an audio type of person here, but I can understand people and they can understand me. So easy pass on that.
What I can't tell you is how good or bad battery life is. Why? See the next part:
Well... now to the downside: it is so tiny, that there seems to be not enough space inside the device to add a standard charging plug. Which is why it comes with a "cradle" which has a micro-USB port on the backside. And here's where the problem started with mine: It just wouldn't charge. I bought the gadget in May 2012(!) and the manual essentially said: "Put in cradle, LED will flash red to singal charging". I put it in, plugged in the AC adapter... nothing. No red LED. So I figured it might be a typo in the manual. But when the headset stopped working a few days later, I knew: it didn't take on any charge. I changed the AC adapter: nothing. Then I somehow got tired of trying and didn't really need it anyway...
...fast forward to yesterday. I saw it lying on the shelf again and got ticked off: it wasn't working and I was going to take a look at it at the very least. I measured the output voltage on the terminals in the cradle: zero. Or at least close to zero. After some pointless Googling that had articles about "a chip in the cradle" I discovered that the cradle is held together by two tiny screws that are taped shut with a sticker. Bring it on!
The cradle proves to be just a USB-plug, a PCB and the cradle contacts. Not even a single hint of any other electrical part. No Chip. That got me thinking... maybe the flimsy USB plug was broken? So I measure the voltage on the PCB: 5V... ummm... and the voltage on the copper terminals: 0V. ooookay? Well, it turns out that the cradle contacts were a tad bit too short to protrude from the PCB and the solder points were just there for decoration. It was a bit tricky (the PCB is only 10mm by 20mm give or take) but I managed to get the old solder off, put the cradle contact in properly and solder it back together. Lo and behold: there IS a red light on when I put the headset into the cradle. After a night of charging, it seems that it held a good portion of energy even. Paired with my phone easily.