I have this, and a (more expensive, but popular) Petzl Tikka XP2. I bought this for (dark) early morning running.
I agree with others that the vertical adjustment is a little flimbsy, and the head bands are only just about long enough (not sure about being able to put it on a helmet). The focusing is very good, and it is quite even over the focused area, however wide is maybe not wide enough for a sitting with a group (but perfectly good for walking/running). The build quality is adequate, it does have a cheap feel, but other than the vertical adjustment seems sturdy enough for a long life.
The button action moves between modes "Bright -> Less Bright -> Strobe -> Off -> ..."
Comparing to the Tikka XP2, it is much brighter, but more focused. The Tikka XP2, I think is bright enough for camping and walking, and spill of light is much better for groups (you see more in your peripheral vision). The build quality on the Tikka XP2 is also much better, the button action is much better, the head straps are wider and seem better quality. It is also much smaller so will fit in a pocket.
So why did I buy the SuperLED torch? This torch is much Brighter (more reach to see when running), more focused, and has a over the top head strap. It is also half the price of a Tikka XP2 (and for me complements it). It also uses AA batteries which I prefer, rather than AAA batteries.
Battery Life...
This really should be in the product information above, it is not even on the product's box! I've not had the torch for long enough to actually drain some batteries, but I have measured the battery current and hence can estimate battery life. These tests were done using NiMH batteries (typical modern standard rechargeables). These rechargeables are good option as they provide a fairly constant light output, until they are almost fully discharged.
ON BRIGHT (460mA) which is around 4-5hrs with a 2500mAh rechargables.
ON LESS BRIGHT (110mA) which is around 15-20hrs with a 2500mAh rechargables.
(I'll update if my experience is different from the values stated above)