The Bottom Line: The Bindi is an expensive, top of the line headlamp with powerful lighting in one of the smallest and lightest packages on the market.
The Petzl Bindi is a handy light that straddles the emergency back-up light category and the standard high power rechargeable category. It's a little pricey as headlamps go, though it's only slightly more expensive than the Black Diamond ReVolt, which has the same specs (using the weaker rechargeable nickel batteries). The main perk is that it is much much smaller and lighter. The main role I find for the Bindi is a lightweight headlamp for multi use that also doubles as a superb emergency light. I've started bringing it along as my backup light because it weighs less than three alkaline AAA batteries: As a wise man once said, "Carry your extra batteries in another headlamp."
In terms of comfort, the light is pretty decent. The tension cord strap isn't that uncomfortable. I have run with it, and I haven't experienced any slippages or chafing, even with a sweaty forehead.
The light modes are pretty good. I rarely use much more than the 5-lumen setting because it's normally more than adequate for walking about in the dark. It is occasionally handy to blast the light up to 200 lumens to find a trail fork in the gloom or spot something further off. A handy light on the front uses colors to tell you how much battery life remains, and when it gets to be within 15 minutes of running low, the light flashes to let you know.
One huge perk of Petzl lights that is badly marketed is their performance at low battery. Many other lights will advertise much longer light burn times compared to Petzl. The reason for this is that Petzl uses regulators in their Constant series lights. These guarantee you will get the max amount of power for the listed time. Many other headlamps list longer battery life, but they will be pumping out 30% power in their highest mode. This means that you know how much time and power you have with a Petzl lamp. You can run it on low power to conserve power and use the high power only when you need max brightness.
The minor downside to the Bindi is it's integrated battery. You won't be able to just swap out new ones when you need too. You can charge it with a powerbank of course, but those definitely increase the weight.