Euro lights make a huge difference and are a very important upgrade for those who are concerned about proper night-time illumination. Instead of the crappy US spec pattern, the Euro lights use a very precise beam pattern. There is very little light above the horizontal to the left of the car to avoid blinding oncoming drivers. In addition, the light beam steps up at a 15 degree angle to the right of center in order to light further down the road and light up road signs on the right side of the road.
I have noticed that the newer Mercedes do utilize this pattern as stock equipment in the US, interesting.
-Ali Al-Chalabi