nice job so far! for a crit, what is turning it a little down for me is the metal... If you look at your concept it looks much more contrasty and crome-like, you should maybe try to darken your diffuse a lot and give it more contrast through the specular map. That's more or less how crome materials are in real life, dark…
Looking nice, keep at it. I have a few quick crits though. -Not specular enough.. look at the reference, it's a very shiny/reflective metal. Diffuse should probably still be darker. -Chest light thing is too high up. Compare to reference. -Proportions looking a little too child like, not heroic like the ref. head is too…