Please don't misunderstand my intentions.....the stock headlight is not very good, and it can stand some improvement. However.....I am not a fan of throwing LED lights into a housing it was not built for, as the low beam light is not well controlled (and it is not legal to install the LED lights in normal bulbs....that is why all the sellers state that the bulbs are for "Off Road Use Only". The vertical cut off is not provided in most cheap LED lights, and you end up throwing a lot of light into the faces of the oncoming traffic. There are several folks in the area where I live that have put the LED lights in their cars and trucks, and when they are behind me I can see the outline of my car reflecting in all the road signs and bridges as we pass.....and my rear view mirrors are blinding (and it is even worse when they are coming straight at you on our narrow county roads).
This is what a proper headlight does on the low beam - it limits the amount of light that shines upward.
When you put a bulb in without the proper vertical control, the light shines upward and is blinding to other drivers.
Good LED H4 bulbs have a vertical cut off built in to the low beam light. You can see the bulb below has a molded shield that prevents the low beam light from shining upward.
The CREE and other lesser quality bulbs don't have any vertical cut off built in, and they don't properly control the light shining upward when using the low beam.
There is a thread in the Honda ST forum that shows the work they did to modify the LED bulbs to get the needed vertical cut off for the low beams. This reduces the "glare" that results when the bulb doesn't control the low beam properly.
http://www.st-owners.com/forums/showthread.php?146534-How-to-modify-H4-led-to...