I purchased this light recently after acquiring a Bell Muni Bicycle Road Helmet in Geeky Hi-Visibility Yellow -- and noticing that the helmet has a bracket on the front for the Flea. I find that in flashing-mode, the Flea's battery indicator light is on the yellow setting, which means it still has between 25% and 75% life left, after two 90-minute bicycle outings.
I haven't tried this yet at night, but can't really imagine using the Flea as a see-where-you're going light if you travel at any decent speed; it's much more in the hey-look-out-for-me family, in my opinion. But I have headlamps to illuminate the path at night, and this is a handy, wonderfully easy to charge, lightweight and surprisingly bright flasher even in full daylight.
If you believe that an ounce of prevention is worth a pound of cure, this makes a great enhancement to your visibility in traffic.
So, the positives:
* Practically weightless
* Easy to charge from a USB port
* Easy to mount on the right Bell helmet
* Battery charge is sufficient for long rides, at least in flashing mode
* Quite alarmingly bright, which of course is what you want when you're riding in traffic
As for durability and longevity of this light, I don't have enough time with the Flea yet to comment.
