this ia a harder question for me to answer, as it sort of comes down to what all you need the light to do
some of the best for working on things, are super bright, but from one's I have, battery's don't last so long
some of my smaller LED one's
batteries last forever, but they don;'t make a ton of light, enough to get into a stand in the dark or out, and some other things,
so all maybe comes down to what you need a headlamp for?
I will say one of my fav smaller lights, not a true HEADLAMP one, but can be used as one
has been Streamlight's CLIP MATE lights, small pack easy battery life is long, 40+ hours NON stop, and the little clip allows it to be attached and angled to almost anything to make hands free use easy
but again there NOT super bright lights out there but do have again LONG life, and fit in sm,all pockets or tool boxes /first aid kits or??