Here'sa good thread:
http://www.tahoeyukonforum.com/threads/led-vs-hid-headlight-upgrade.95293/
LED headlight technology is still relatively "new" and its rapidly improving. Right now LEDs have the best success when used for DRL lights,
reverse lights, fog lights, interior lights, etc.... but lack the true penetrating beam pattern needed for low beam lights. The LED lights do not produce a halogen type light pattern and also the projector
housing you have is expecting a halogen bulb to be placed in it. They have designed the headlamp housing to know the halogen filament will be X inches from the tip of the bulb and precisely angled all sides to reflect that
light forward infront of the vehicle. The thing with LEDs is most commonly, where the LED lights are on the bulb and are producing the light are not exactly where the housing is meant to reflect light. So a lot of the light is not reflected into the correct direction and light is lost inside the headlamp. Also, the pattern of the LEDs is to push light in only two directions on the bulb, where a filament of HID bulb does it in a true 360*. (there are 360*
LED lights also, they are even worse than the normal LEDs that are only on the two sides). So in a brief summary, LEDs are great, they use a FRACTION of the power than HIDs or Halogen, they do not get as hot either, they are straight plug and play, and they go from 0-100% light out put instantly. BUT, they are still lacking in the true directional
light and penetrating light. They are better than stock
halogen, but not better than HID
kit.
