What makes one HID set up better than another?

Better yet, What makes for a good HID set up?

I'm under the impression that HIDs are supposed to put out far more light than a normal headlight. I have seen a lot of, and even owned some, that didn't look any different than normal headlights. Then again, I have seen some on cars, trucks, even sportbikes, that are so bright, they alter the migrational patterns of birds.
What are some brighter than another?
and I don't mean more glaring. I mean, they actually put out more light.

What is the difference between a 35w and a 55w system?

What is up with that youtube link that comes up on google for a 100w set up?

Is there a particular bulb style that is better than another?

What makes a good ballast?

Someone said that the light output of the bulb is limited to the ballast. is that true?

Is it possible to wire two ballasts to the same bulb? If you could, what would that accomplish?


There is a lot of information out there. Just most of it is geared towards the sales pitch for whatever bulbs or kits that site is selling. I know there can't be 2 dozen different "top of the line" "best ever" set ups all at the same time.
I also know the $40 dollar set ups off of Ebay shouldn't be able to perform anywhere near as well as the 2-300 hundred dollar set ups you find elsewhere.
So, whats the difference?