I think your low poly can use improvement to their faces. Their high-res counterpart has quite nice faces, although maybe lacking characteristic, but the low-res' faces are kinda plain and bland.
well, no , it looks like a babies face, or a fat mans face. But thats because you havent put in any definition yet thats all. Just keep looking at peoples faces to notice the important curves.
Looking good ! Just a tip though about the face presentation, the camera focal is not really adapted for face close-ups, it deforms the face quite too much. Here's a little example to illustrate my point.
Day 7 Please Critique, need to understand why the face still looks off New face sculpt with closed eye. wanted to concentrate on other areas of the face. such as the nose and the mouth different shadow render
and here's the gloss map for the face (using GGX reflectivity): Almost all of the detail in the face comes from a combination of the base normalmap and a detail normalmap. the face has a constant reflective value (0.028) for the entire area.