Originally Posted by Ol' Timer
I have also read that some people, including yourself, have been dissapointed with the results.
It is _not_ a good idea and it does _not_ work very well. As the article says, LEDs are highly directional, aiming their output straight out, but the Bonneville lenses are designed to catch light coming from the side of the bulb as well, bouncing and refocusing it outwards across the full area of the reflector and lens, so in other words a 1" bulb can fill a 10" lens with blazing red light. If you stick an LED conversion in there, you get little to no side light output, resulting in a red dot in a sea of darkness by comparison.
Yes, very much so. Scroll down that page and compare Photos 4 and 5 to see how your light output decreases when you put the LED conversion in.