Click on my profile and search through my recent posts. I have a lot of good info on LED headlight bulbs, specifically the H13/9008 application.
Most people think that overall brightness for a given LED bulb is better than stock but it really isn't. They see a brighter garage door when they turn on their low beams or drive down the road and see signs light up miles down the road, and think "these things are so bright, its awesome". The most important attribute should be proper beam pattern. And 99% of ALL led bulbs on the market don't achieve it.
In my most recent posts I talk about what to look for when shopping for a decent LED headlight bulb.