I have both the Petzl E+Lite and the Petzl Signal. I keep both in my FAK at all times.
The E+Lite is easily worth what it costs as it is very bright, very small, and very flexible. (can be a headlight, can clip to a hat-bill, can stand on it's own) The brightness adjustability, plus having a red LED, and a flashing function are terrific.
I don't use the E+Lite as an everyday light. This is mostly because of the more costly coin-cell batteries. But those same batteries make it excellent for storage. (~10 year shelf life)
My primary everyday headlight is a Petzl Tikka XP as it is also quite small, uses "normal" batteries (AAA), and fits in a Petzl Poche Tikka (pouch) on the strap of my laptop backpack.
Attached is a picture which includes some size reference. Included; Tape measure, Petzl E+Lite, Petzl Signal, Photon Freedom microlight, Photon Rex, an Apple iPhone, and a set of keys (key pattern masked to prevent duplication)