Relevant thread, I was thinking about putting either better H4 bulbs (like the PIAA's) or LED replacements in my '07 DL1000. Current bulbs are possibly original equipment (11+ years old!) and so could probably use replacing just on general principles, regardless.
Considering LEDs more because I'm going to be running a lot of heated stuff this winter (grips, gloves, jacket liner) and not sure I have enough electrical capacity overall, so LEDs would be a way to save power.
I was also thinking about putting in one of those Eastern Beaver relay headlight harnesses because, well, apparently they're a Really Good Idea.
If I could only do one of the above, which is likely to be the most bang for the buck?