A 1 watt LED running from just two AA batteries is not going to last for a long time.
Sure enough, we managed just under the claimed three hours on full power, just under five hours on low power setting, and a little over the claimed nine hours in flashing mode. Unlike the Ultrafazer 3.0, though, there is no side window on this light, but visibility isn't too bad at more obtuse angles. It does give off some nice peripheral light though, and it is bright enough to ride with at pretty good speeds on unlit roads.
The clamp is nice, easy to fit and very solid in use. We can't help but think this light should be powered by four AA batteries instead of two for better run-times. That said, it's waterproof, very well made and comes complete with two bar mounts. As well as the short run times it's also a little pricey.