I came from having HUD in my 01 Corvette, so it was a must-have for my Mazda 3. The display from the Corvette HUD is projected over the road vs near the base of the windshield in the 3, but hey, the Corvette cost me $51.5K in 01, so I didn't expect a $29K car in 2014 to have the same sophistication. Still, it is a lot better than having to look down at the instrument area, especially at highway speeds.
The other nice thing about the 3's HUD is that it also displays turn arrows when a navigation route has been activated. The arrows give you a quick reminder as to when you need to make a turn.
So all-in-all, I give the HUD a hearty thumbs-up.