I also own the e-lite and like it a great deal. But it is not perfect, it is the smallest, but there is a trade off or two which have been mentioned. In addition to difficult to find coin batteries, the headband is small, not comfortable, and prone to shifting. Again, a trade-off for being so small.

Just a bit bigger is the Petzl Tikka XP 2 Core which has a nice headband, USB rechargeable lithium ion battery, and can be easily converted to eat AAAs in alkaline, lithium, or nickle metal hydride. If you really want to go all out, Petzl also makes a very nice Adapt Tikka 2 Kit that provides all sorts of cool mounting options. Finally, Petzl makes a sturdy carry pouch for this unit.

Two points. One, you can find better prices than the REI links I provided. And two, all this adds up to be a much higher price than the e-lite, but you gain much versatility and dependable power options in the trade.

I also am a big fan of the Pak-Lite mentioned above, but its not much of a thrower and hard to keep positioned in a headband. It is THE emergency power outage or backup light for your BOB because of its extreme runtime using the 9v lithium battery.

YMMV