I think there is a BIG difference though between each of the following:
1. Halogen
2. Factory Installed HID
3. After-Market Installed HID
4. After-Market "Cool Blue" Halogen lamps
Honestly, I'm happy with my halogens, especially since the mz3 still uses a projector to cast the halogen to the road. The aim is nice (for me at least), and I don't blind the people in front of me. This "should" be the same for #2, factory installed HID.
All of the grips about are mostly referred to as #3, aftermarket (i.e. improper) HID installations, usually with hardware NEVER intended to fit or be put on the car. This is usually where blinding occurs. Think about it, these came from European cars, where they (legally) drive much faster than us. Why would they design a car to blind oncoming traffic?
Now, #4. This is also where I fit, and only because I think there is a difference between Cool Blue and HID. While a similar result is desired, I find that the cool blue casts a more effective and easier on the eyes (as a driver) beam of light.
Once Hoen completes the design, I'll probably get a set of blues from them. Because of the projector housing in the mz3, it should do just fine.
But I think that there is a HUGE difference between the two, and certainly between a proper factory install, and a ******* install (I can say that, I grew up in Georgia).