Thanks, Rex. It is always nice to have some good comparative reviews to look at.
There are so many issues with these little wonders, it takes some time to sort them all out.
A lot of choosing is individual. None of the best reviewed lights appeal to me for various reasons, such as the strap-on battery boxes, lack of an integral diffuser, or overly complex controls. Would go with the strap-on boxes if hiking much of the night, though (But why not hike in the day?).
It is so much more pleasant - no hot spots, circles etc. - to hike or camp with a good drop-down diffuser, that the diffuser stays down all the time. With the current availability of high capacity pen cells, I would never accept a battery case strapped to my head. And ultra simple controls are a must: When the lamp must be operated with shaking fingers in the cold pouring rain and the mind is beginning to dim with the approach of hypothermia, ultra simplicity of operation is required.
The onset of one button controls for so many electrical appliances reminds me of the "galloping ghost" RC rudder controls we used as kids. We couldn't afford multi-channel transmitters and receivers, so somebody cooked up a constantly flapping actuator that could operate based on just two modes, ON and OFF, and could be operated on a single channel.
Based on a review here I used a Remington RMHL-2AAA-B until Zebra fans insisted on a recent thread that one AA battery lasts longer than two AAAs. Despite no milliamp ratings on the Eveready lithium Ultimate cells, am trying the Fenix HL21 to see if that is so. Both lights have integral diffusers that eliminate circles and hot spots from the beam, but still provide plenty of light on medium to see all obstacles on the path, set up camp or read in the tent. Dale Waumbaugh posted a positive note about the Fenix on this forum.
Now if only Eveready would come out with rechargeable 1.5V lithium pen cells.