We found the best review of the Princeton Tec Quad headlamp at Backpacking Light, where it's compared with nine other LED headlamps based on ratings on eleven factors. Tests at FlashlightReviews.com are even more technical, and the detailed owner-written reviews at BackpackGearTest.org are based on extensive field tests over a longer period. Outside magazine also tests the Princeton Tec Quad, and more than 20 owners rate and review it at REI.com.
Reviews say the waterproof Princeton Tec Quad is the best headlamp for task lighting, both for household power outages and for campsite lighting. Comparison tests give this 2.9-ounce 4-LED headlamp the best scores for comfort, and the elastic headband is detachable so you can use the Quad as a standalone lamp. A strobe mode is available for emergencies, and brightness adjusts among three levels. A voltage meter keeps light consistent, but only for 24 hours on the lowest setting, although total battery life is as long as 150 hours. It runs on three AAA batteries. If you need red light for night vision, the Princeton Tec Quad Tactical (*est. $37) adds a pull-down red filter.
Based on thorough tests, this review compares the Princeton Tec Quad with nine other LED headlamps, rating each on eleven factors. Some headlamps are lighter or throw light farther, but the Princeton Tec Quad leads the pack for both comfort and value.
Review: State of the Market Report: LED Headlamps (2007), Rick Dreher, Mar. 2007
This site specializes in detailed technical reviews of handheld flashlights but also tests headlamps. Based on thorough testing, the Princeton Tec Quad headlamp is recommended as the best four-LED headlamp powered by three AAA batteries - with praise for its battery life, sturdiness and ease of use. No drawbacks are noted.
Review: Princeton Tec Quad Headlamp, Doug Pribis, Jan. 2006
3. Backpack Gear Test
Five experienced backpackers review the Princeton Tec Quad headlamp here in great detail, reporting on extensive field tests over a longer period of time than most reviews cover. Some testers are disappointed that the voltage regulator keeps light consistent for only a few hours, and other minor drawbacks are noted.
Review: Headlamps - LED, Reviewers for BackpackGearTest.org
4. Outside Magazine
Based on extensive field tests of headlamps, the 2006 gear guide at Outside magazine recommends the Princeton Tec Quad because of its voltage regulator and battery meter.
Review: 2006 Gear Guide: Princeton Tec Quad Headlamp, Tim Murrell
Nearly 20 owners review the Princeton Tec Quad headlamp here, several reporting that it's useful for reading in bed or completing household tasks as well as on camping trips. Owners say it withstands being dropped well, though one reports cracks around the switch.
Review: Princeton Tec Quad Reviews, REI.com editors and contributors