Overall I am impressed with the light output. Huge step up from halogens. My daily commute is 50+ miles with 50% of that driving in the middle of the night and it's really nice to be able to see further ahead of my car. I feel much safer with these. Installation took me about 15 minutes mostly due to fighting with my airbox to access the passenger side dust cover. (I won, but barely)Having said that I am skeptical of the longetivety of these bulbs. Having the built in fan adds more complexity and more things to go wrong. (although I could say the same about my Volt, and it has been extremely reliable) My housings are also projectors, so the bulbs are sealed behind a dust cover, which the fan on the bulb is really close to with the cover on. Only time will tell how these hold up. It's winter time now, so I'll be interested in seeing if warmer ambient temps will effect them.UPDATE: it's now September and the passenger side fan has a really loud hum for the first minute or two after start up. It's so loud that I can hear it driving down the road, over my radio. I will be looking for better quality replacements here soon.