Energy dissipation, beams cut-offs, and the kind of light emitting LEDs utilised are all important factors to consider. You can't have just one without another with LED headlamp technology, and in the end, the adage "you get it you pay for" still holds. You're wasting your money if you have fantastic Philips or CREE LEDs in your product but don't have the tech or temperature control systems to effectively interface with them. Thermal control is critical for extending the life of LEDs. The LEDs should be brilliant, but they should also endure a long time. Beam cut-offs are also necessary...