I agree with you on the curved HUD, but with one exception, more of an add that is missing that I think would make it 1000x better.
Since they are trying to make it look like a realistic cockpit windsheild, what they need to add is a bit of shading on the perimeter & a glare spot at the apex of the curve. Even if they made it 95-99% transparent (to not block your view) would make the curved HUD look really impressive. The way it is though, IMHO makes the HUD look kinda 2-D & flat =(