One other thing to be aware of, regarding the legality issue (and it's relative to federal DOT regulations, not state lighting laws):
Although most decent cops won't give you any trouble if your lights are properly aimed and setup to work effectively, there is a different risk. If you are involved in an accident (probably has to be after dark), even if the other guy actually caused the accident, his insurance company can refuse to pay your claim because technically you're not operating the vehicle in a legal manner. And your insurance company can refuse your claim as well, for the same reason. It just depends on how much of a jerk the insurance companies want to be. But they do have that option, and in the case of your own insurance, you already agreed to operate your vehicle in accordance with all local, state, and federal laws, when you agreed to your insurance policy/contract.
I don't mind HID's, as long as the system is set up correctly. When they're properly adjusted, they tend to put more light on the road, and less light into oncoming drivers' eyes. I don't think that funny HID colors like blue and purple are appropriate or effective, and I've seen lots of crappy HID installs that put the light pattern far too high and are dangerous. The only drawback, really, is the legal issue. And there's enough knuckleheads out there trying to make their car look "cool" without knowing how to do a proper job, that I think there's a need for the legal restrictions.
Spott