Well, they seem to offer load resistors, etc. for the different current draw, but it could be a waste if the LED is too big to fit in the housing. I would definitely do it if I had the time, patience, etc, it would look cool and the output would be great. Kinda expensive in the long run though.

TBH, though, my headlight output is just fine, and while all the other bulbs are a little dim by today's standards, they're perfectly adequate.