I have a HUD in my 6er and love it, and when I get an X3 I'll get a HUD in that too. The main benefit to me has been "ticket avoidance" since I can tell in a microsecond whether I'm speeding when I see that police speed trap down the road. I estimate it's saved me many hundreds of dollars in tickets (not to mention more hundreds in jacked-up insurance premiums
).
Of course, having it tied into the Nav system is cool too. The HUD also shows you alerts (flat tire, service alerts, etc) but that's definitely a secondary benefit.
One last tangent, it's "Head Up Display" (not "Head
s Up"). For a couple of decades the fighter jocks call it a "head up display" in their fighter jets, whereas "heads up" is what you yell before a fly baseball conks your buddy on the head.