Having a light that can run at lower brightnesses for long periods is very useful. Headlamps are very useful.

Personally, I prefer lights that run om 18650 lithium ion rechargables.

My current lights of preference:

Zebralight headlamps. Very compact and light 18650 form factor. Downsides, button easy to bump on unintentionally and non intuitive UI. Can't run primary lithiums.

Spark headlamp. Better UI, can get optional lens to convert between full flood and more focused. Can run 2x123A or 1x18650. Downsides, heavier/bulkier than Zebralight.

HDS Rotary. Dim to bright with the turn of the knob. Very intuitive UI, bombproof. Pending 18650 tube. Downsides, cost.