Nice article on the benefits and costs on "blue headlights".

Daniel Stern Lighting Consultancy and Supply

Thanks Michael for that interesting read about headlight bulbs.
I know that since the legal bulbs are 55 watt that overall they still have limited low beam output. Only when u hit the highs do you obtain the higher wattage. This is why many, if they have separate fogs available, may do a mod by obtaining a high beam bulb and start trimming one of the tabs to make em fit. I did this on my Jeep and wow what a nice improvement.
I always wondered if your low beams were correctly aligned, if you could mod a high beam 65w bulb and not get flashed!
There are other bulbs by Hella (rally) that may approach 100 watt, but may start to melt wires and housing... I dont think as daily use, that they are long lasting either.
In both the PA and Jeep I run PIAA bulbs because I know that they last a super long time, and have yet in 3 years to replace them. They gave whiter appearance and better roadway sign illumination, compared to silver stars. Never tried nighthawks, though I would give them a try one day if I need to.

personally, i dont use the "blue" bulbs for any purpose other than to help me at night. i suffer from night-blindness. if there is an oncoming car, and ive got normal headlights, i have no idea where the road went. with my HID lights, the road is a nicely contrasting white color and i can safely drive at night because my eyes can focus on the white rather than the yellow.

The only time I have noticed a difference with blue bulbs is at night time with snow on the road. For some reason, it contrasts better.