The biggest complaint I have with headlamps is the user ends up blinding others with them due to poor light discipline. I use to use a headlamp a lot in the jungle and found out it was better to go with a simple flashlight for most chores. We have "banned" them for participants going with us on alligator/caiman night hunts since people turn them on to look in the bottom of the boat, in their pack, or just have to turn a light on because they are freaking out because something's crawling up their arm. They wind up lighting up others in the canoe and scaring all the gators and game away. Headlamps are great for individual use when you're alone but they suck for groups, IMO.
Not saying they're not a great invention but the more I go to remote areas the less "great inventions" I carry because keeping it simple seems to work better.