I recently converted from Halogen bulbs to LED bulbs, specifically the following.
LED BulbsPros :
* Reflective surfaces really show up now
* The light is a bit brighter, not HID bright.
* In winter conditions I perceive I can see snow, slush or ice on the roads better.
Cons :
* Depending on your housing the light pattern varies
* If you buy LED's that allow you to "clock" the bulb for the housing you will not blind drivers and get a better beam pattern, however they are expensive.
* Due to my OEM reflectors I have what I think are "dead spots" which are no as bright of light as other areas of the road.