The promotional video is deceiving. The way the HUD is described is "infinite focus point", meaning it floats in your vision and does not appear as a flat screen, they way it looks in the video. As an infinite focal point, it should be very easy to look or see "through" the image to what is actually behind it without much though, while remaining intuitive.
Probably impossible to capture the infinite focus point on video. Being able to keep your eyes forward and see your speed on the HUD alone is worth a good bit as it avoids having to speedo check, each time taking your eyes off the road and refocus at a point close to you.
If you look at this as what it is, the first to market of its kind, it is quite interesting. Worth $1400, up to you, but for sure, in the future it will get cheaper and gain more features. Once it has some speakers and the ability to connect via BT to a phone and customize the size and information on display then I think it's worth the money.
Also: Comments about durability of the electronics. Small, well built, PCBs with SMT components can usually handle impacts that would break your skull (read 100+gs) before you break the board, of course construction quality is paramount though. The camera, wire connections and batteries are more of a concern. In particular, a LiPO/Lion battery going critical that near your head should be a worry in a crash.