I have both lights and have had both mounted in my patrol vehicle. I personally think the Viper is slightly brighter as the optics are better. With the Viper, the led light comes from the bottom and is reflected up and out with mirror reflectors, allowing for all the light to be dispered as a whole footprint, where the Avenger has the linear optics directly in front of the leds, which then disperses the light outward. The flash patterns and mounting is much better with the Avenger, but both will def get the job done. Viper is slightly cheaper i think, but the price difference is not enough to make a huge difference.