I have a Princeton Tec Aurora that I've had since 2006, with which I'm still very happy. It is regulated, so the light stays bright until the batteries are just about kaput. Also, being regulated, it can use lithium batteries which last a lot longer and work better in cold weather. I have no intention of replacing it. I did try a Petzl e+lite a few years ago and gave it up because it's not bright enough for night hiking. Saving 2 oz. was not worth it when an emergency arose requiring night evacuation!
My headlamp isn't just for backpacking! I use the Aurora a lot around home because it gives me hands-free access to dim places like under-counter cupboards, etc. It shows no signs of wear. It goes with me on auto trips, too. Unfortunately, as I discovered when searching for one for my youngest grandson, this model has been discontinued.
If I were searching for another headlamp I'd look for several things. First, regulation, as I mentioned above, and the ability to use lithium batteries. Second, as mentioned by BZH, a switch that can't get turned on accidentally in my pack. Third is enough lumens so you can see the trail (with its rocks, roots, holes, etc) when hiking in the dark.
May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view--E. Abbey