This weekend, I replaced my stock H4 bulb with an SpeedMetal LED I purchased from my local Cycle Gear. I chose them as the lamp had decent reviews and Cycle Gear has a good return policy in case it does not work out.
http://www.cyclegear.com/SPEEDMETAL-LED-Conversion-KitInstallation was pretty strait forward but not quite plug and play. The metal ring is on a color that slides over the the front of the lamp to allow you to install the parts that normally slide over the back which can't because of the heat sink. It does have the flat edge on one part which I have read several lamps did not. The only thing that did not fit was where the plastic for the screws holding the metal ring prevents the locking collar from seating. I trimmed these with a hack saw as that was what was handy, but a Dremel would have been a bit easier. After that, things fit fine. I did not find a good place to mount the module so I used a couple of zip ties to attach it to the existing wire bundles.
The beam is not as focused as the original lamp, but is significantly brighter. I don't get as distinct line between light and dark which is helpful when adjusting the height on the garage door, it fades out a bit more gradually. The light is pretty well contained when on dim. On bright,
everything, including the upper portion of my garage door, gets lit up. It is nice and even with no discernible hot spots, but a lot of the light is needlessly going up when on bright.
I briefly road tested it, but did not get out into a dark area so the exact beam was hard to distinguish from the street lamps. Assuming no rain on Wednesday, my ride takes me to a much better area for testing. I didn't mind the stock lamp on bright, but dim was just horrible. The light is much whiter from the LED and dim seems at least as good, but more road testing is needed.