ohh they do... i will not say the best.. but vs 100w bulbs.. it lights up so much more.. what i should say.. anything that reflects.. like signs.. they are lit up and reflecting before you can read them.. but its not like they are "light on them" the signs just glow in the distance..
mk1 jetta has high low and a high... my b3 wagon with the de conversions have a low and a high.. and that one i rewired so the lows stay on when highs hit..
having a h4 with both high/low on at one time = blown bulb..
another thing.. playing with bi-xeion (sp??) switching from high to low.. is freeken odd as hell... since the bulb its self moves its got no high/low on at same time aspect.. you will see how its odd...
now i do not know the streets you have or use... but be careful on color..
my area is 90% blacktop... white is great.. blue sux...
out of town on concrete.. blue is great.. white is ok..
both above in non rain situations.. in rain... blue reflects off black top.. all you can see is the lines.. it is horrid.. this goes for blue h4 or hid.. white... in rain on blacktop... LOL.. vs a 100w bulb.. does not reflect light as much.. but still reflects..
i highly suggest a good set of fog lights (not crappy ones.. spend the coin)... wired up so they can be run with only parking lights and with high beams on..
why...
the hid light up fog pretty good... if in really crappy fog.. ill kill my headlights and let the fogs do their job... why highbeams.. they fill the gap between highbeams and front of car.. work as a "cornering light" so on...
ive been playing the light game way too long...

any wiring questions.. ask.. relays are cake.. good grounds and power source is night and day differance..