Hi Archytekt,
Congratulations on a great build! I especially love the faceplate and mouth grills!
The piece is beautiful as is, but since you requested a fresh pair of eyes, I'm glad to point out a few things.
I've attached a couple photos up for comparison.
Like Toxx pointed out, the vocoder is a little thin, and could be widened. One detail about the tops of the vocoders is that they basically taper (depth-wise) and disappear right into the helmet.
Also, on the front "looking up the nose" shot, the bottom sides of the nodules are not so level, but angle up more (that may be a pepakura model issue which was corrected in the newer versions; my apologies for that).
Finally, the space between the ear discs and the sides of the ear seems too wide, the space is actually pretty narrow (I've included a shot of both ears, since one is so much higher than the other...)
Remember not to take all the sizes in my photo comparisons "too" literally, as the lens really distorts things... on the closeup "front" shot of my ANH bucket the nodules look more big in proportion than they actually are..
Hope this helps! Great job and excellent craftmanship!