I am by no means the most qualified critic but I guess I have a little advice for your Coteaz model. You need to keep the lighting source consistent. It seems like the light hitting the left arm and the right arm are coming from different angles. Also, you need to go completely to white and black on each armor panel. The legs need to achieve a true white and a more consistent pattern of light striking it. The light should have a similar pattern to the left arm. You need a defined horizon on the chest panels. Basically, what you did on the left arm was perfect, you just need to recreate that effect all over. I know this is long and rambling but I guess my best advice would be to go on CoolMiniOrNot and study some other
NMM Coteazs people have done, it should help you get a better idea of your light sourcing and how the reflection should look.
edit: Although it is SENMM I think this model would help you
http://www.coolminiornot.com/79224?browseid=4105645