I sat down and watched A New Hope, last night, to systematically go through some of the complaints I'm seeing here in terms of accuracy.
I think the chest armor being a little on the bulky side is actually accurate, depending on the trooper. The short-neck appearance is also accurate for the same reason, seeing as some troopers are shorter or thicker than others. Remember, these aren't copy-and-pasted CGI models - there are humans in there. For that reason, if I had two of these, for diversity's sake I would leave the first as-is and only tighten the chest plate and elevate the head on the other.
For the folks who don't have this, yet, and may be a tad concerned - The slightly inaccurate cup/cod seems much more out of proportion in the official photos than it is on-hand. We all know how that is, canceling a Sideshow based on a photo, then finding out down the road it's actually a great piece sitting on the shelf.