While that isn't much of a range..

The fact that it's "projected" to appear at nearly the end of the hood was, in my opinion, WAY MORE AWESOME. It's more useful there, so a small change in height = a big change in perception.

HUD in the Lexus line (where offered) was projected much closer up. Less useful, because you kind of have to scan down to view it. It is not (so far as I could tell) adjustable, either. I've seen pictures of the actual assemblies and the BMW HUD array is actually very impressive - someone put a lot of thought into it. Color, too (even if not implemented completely)