When I’m using a headlamp, I’m most commonly underneath something on my back working on it, or I’m on my feet walking. I’ve owned the Niteize strap and it’s marginal for the first use and basically worthless for the second — you cannot angle the light effectively.

My favorite lightweight headlamp is the Nitecore NU20. From experience I can tell you it discharges very slowly while banging around in my laptop bag. My favorite lightweight headlamp that takes primary cells (instead of an onboard rechargeable battery) isn’t made any more, it was the Fenix HL50, which could take either 1xCR123A or 1xAA. No affiliation with either company.