The first guy (top row) looks much better and metally because of that strong highlight and more smooth, cylindrical look, so good direction you took him in there. The middle top row guy improved as well, but feels like he was shaded a little differently than the first one. The first guy kind of smooths from that highlight into the red with that orange ramp as a buffer zone, where as the one in the middle goes straight from the highlight color to being red. I think the first one achieves a better feel, honestly, so you might consider shading him in a way consistent with the other. The far right one, however, just feels noisy and textured with that dithering.
The boots for the middle one also display a rendering that is conveying well as metal, with that dark shade right up against the highlight - nice and chrome-y feeling, you might see if that shadow-highlight bumping will benefit the red armor parts as well.
And not to derail, because this is on a totally unrelated note toward the piece, but I did want to sing my praise for Dropbox for non-image related things. I just discovered it and have been using it to keep all 3 of my computers synced with all my client and art work files instead of constantly fearing that the thumbdrive I was using to keep it all accessible wherever needed was going to get lost or broken. Hooray for dropbox
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