HID Headlight conversion

If it lights 4 lanes of traffic what does it do on a 2 lane blacktop when oncoming traffic is 3 feet away and looking right at you?
When it was aimed correctly, which it was, it was no worse than looking into any other headlamp. I can say this because I had a friend ride the bike one night while I was driving at him form the opposite direction. I believe it was not about how bright it was, but the color/spectrum of the light. A light does not need to be blindingly bright to be effective. The light I am talking about is in the same family as the one our resident lighting guru mentioned. I am sure Dan can explain it far better than I.......