my dads c5 has it and it is awesome and is not distracting at all, looking down at your regular gauges is more distracting then the heads up display.

 

+1

My Grand Prix GTP CompG had one, it was awesome. You may think it would suck, but if you ever own a car that actually has one you will change your mind. If not, you can always switch it off.

Tim

 

My wife has the HUD on her Buick Rendezvous.

It really is a nice feature.

It does not just project the image onto the windshield.
It's an optical effect that projects a hologram that is floating above the front bumper. (7 feet from your eyes)
So not only can you leave your eyes on the road, you don't have to re-focus your eyes as much.

It's sort of like looking into a deep hole, but it uses a bunch of mirrors.
This is probably the expensive part.

It has a dimmer so you can set it to any brightness (or off) and an UP & Down to raise and lower the image.