I can't say the same as Jason.
I bought a pair from Thomas last summer and tried them in my car. When you stand in front of the car and look down at them, wow! They are so much brighter.
The problem I saw with them was that you can't aim your headlights anymore. That distinctive cutoff you get with H4s is gone and all you get is a super bright blob of light like you had with ancient sealed beam headlights. I am using Bosch H4s.
I found the beam to be aimed too high, and I ran out of adjustment trying to get the beam down.
In the near field (say 0-20m) they really do illuminate quite well. The bad thing is that they illuminate above about 3' quite a bit. Sure, you get to see lots, but when you are blinding oncoming cars, you risk them losing track of where the road is.
When you click on your hi beams, all they do is get a little bit brighter. The aim doesn't change. The far field was poorly illuminated. After I switched back to the old incandescent H4 bulbs, the far field was greatly improved on Hi beams.
The incandescent H4 bulb has a filament that is smaller than the LED. Because it is smaller, when placed at the focal point of the reflector, the light coming off the reflector is much more coherent. IOW, the light is parallel and not diverging. The larger light source of the LED can't be focused properly by the reflector.
The reduction in current draw is a big plus to them. The LED headlights draw less current than your incandescent brake lights!
