My feeling about light numbers is that they leave a lot to be desired. I would put the Luxos U up against any of the battery lights for the amount of light it puts where you need it. You would need a 3d map of light flux to convince me that it's not as good.
Battery lights are always going to win on the grounds of strict numbers. You can only get 500mA out of a dynohub, whereas you can put 2A through a modern LED. So if they bothered to put decent optics on a battery light, there would be no contest