To be honest, a HUD is cool when you first have it, but it's not that different from a display dash on the S... most likely an LED dash is better at actually displaying the information you need, and more of it. HUD is simply cool, at the beginning.
In many other cars, the info on the HUD and on the dash or monitors are pretty much the same. They are mostly redundant. I don't feel HUD has something so amazing or must have. Very little value.