For $12 more, you could buy the MagicShine, highly rated in a recent MTB Review "LED light shootout" http://reviews.mtbr.com/blog/category/lights-shootout/.

Lumen ratings don't tell everything. For one, is the value quoted for the bare bulb or the light with reflector and lens (lower than for the naked bulb)? You're usually not told which it is. For another, is the beam pattern useful for cycling? It's pretty hard to tell unless you can see a reasonable comparison test such as done in the MTBR shootout.