My Audi has a HUD and it's great. It just becomes a part of driving and I find myself never looking at the dashboard anymore.

The adaptive cruise control, speedometer, and navigation is all available on the HUD -- it displays at appropriate times -- and is gone when I don't need it. When I'm about to hit a car in front of me, it gives a red warning that gets my attention.

It's really quite functional, and not distracting. You can dial-up and dial-down the contrast, which is worth doing. For me, it's easy to ignore if I don't want to see it.

But maybe, just maybe, it doesn't bother me because I grew up playing video games with health, points, and other metadata in the corner of my eyes growing up. :-)