Effective low beam lights are about brightness (lumens), and even more critically, pattern of light distribution. Bright lights, including LED's, are an absolute irritation and hazard if aimed improperly, or as is more common designed with not much attention to pattern. Ideally, low beams should have a sharp cutoff to prevent glare to oncoming drivers, and an even dispersal of light to the sides for illuminating the idiot squirrel who's about to run across the road as well as distance to illuminate the idiot deer with the same idea.
As a testmonial, the Cibie H4 lights (like Daniel Stern sells) go 500-700 feat down the road on low beam, illuminate roughly to the sidewalk or more sideways, and are sharply cut-off.
Here's the isocandela scan of a Cibie 7 inch H4 on low beam. Note the relative concentration of light below the horizontal median line, and the relative lack of high candela light above it, with a slight upwards tilt to the right to see signs and so forth, and a corresponding down angle on the left side to limit glare. That equals less glare to oncoming drivers, and more light where you wish it to be -- on the road. They are relatively cheap to get on Amazon.com, and doubly great if you get the relay as suggested above. Also, go over your connectors in the headlight circuit, including the ground. I soldered each wire into the connectors, and polished off each male connector and the ground eyelet (grounds at the voltage regulator screw) to a shine. The headlights look a white almost blueish tinge with an excellent pattern now, but I've never been flashed by other drivers at night.
