Well, what's going on is that lumens and candlepower really are different. Lumens is the total amount of visible light put out. Candlepower is the amount of light put out per solid angle. I'm no expert on solid geometry; however, an extreme example would be as follows: a laser pointer has LOTS of candlepower straight in its beam (maybe millions or more), but has very few lumens, b/c the light is almost 100% concentrated in the beam. The cateye LEDs tend to produce highly concentrated beams, with very little light scatter. So they have few lumens and lots of peak candlepower.

As to which is more important, well, it's highly subjective. I prefer having overall more light, with a good beam spread. Some people prefer having a powerful spot that they can move to where they want to see clearly. Good light manufacturers try to come up with a compromise b/t a spot and flood, and this IMO is the biggest difference b/t a bike headlight, and a flashlight mounted on the handlebars, namely the superior beam pattern.