We've tested dozens of lights over the last couple of months, some great, some with their problems. One of our most recent reviews was that of the Gloworm X2, which we rather liked...
It's hard to believe that the X2 could be outdone on weight/bulk - output ratio, but this X1 has just turned up and it's the first bike light in the world to use the new Cree XM-L U3 emitter. Output is lower than that of its bigger brother, the X2, but with over 850 lumens output for a head unit weighing only 58grams (and that's including mount), we're liking the sounds of it as a head-torch combined with a bar-mounted main light. At that weight you'd hardly notice it!
It's only just come through the door, but we're already seeing the Gloworm X1 as being a great head-torch. Especially if the X2 is anything to go by. Full test coming soon.
More info: Gloworm X1 light