Chris Colney wrote a review of Princeton Tec Apex Headlamp - 275 Lumens on March 13, 2014
Familiarity: I've put it through the wringer
Holy. Crap. This thing is bright. From shoveling out the driveway at ten at night to working the night shift on the fireline to late walks with the dog, this light gives you the ability to see and to be seen. After retiring (breaking) my old PT triple LED headlamp from 2008, the step up is incredible. This light offers excellent battery life which is metered so you do not experience the slow tapering of illumination, it stays bright, then dims rapidly. Personally, I like this. Especially since there is a blinking battery indicator that lets you know when you're at >40%, <40%, and <5% so it's easy to keep an eye on your power level. The brightness settings differ enough in their illumination powers to actually encourage you to utilize this function. The two buttons for switching between the maxbright LED and the ultrabright LEDs takes a little time to learn, but it's easy enough to figure out. You can then go from high to low setting in either light source. The light and battery pack are a little on the heavy side but for the light output, it's a small price.