you've got some strange shapes going on in the texture, notably the lips/nose area and forehead, and everything feels very undefined except for the eyes, which are very sharp and bright. can you post the diffuse?
Yeah baking AO into the diffuse is for the 'old' non PBR workflow. http://www.marmoset.co/toolbag/learn/pbr-theory http://www.marmoset.co/toolbag/learn/pbr-practice http://www.polycount.com/forum/showthread.php?t=146677
I think you took the article too seriously, having different diffuse maps than Epic doesn't mean it's bad. Unless your scene feels like it's lacking something, don't change a thing.
Players would never notice if the same map was used in two seperate games. That wouldn't be a concern. Plus, with some slight diffuse/roughness tweaks to fit your personal environment, there would be nothing to worry about.
What purpose does the blurry noise on your diffuse and spec serve? To me it seems unnecessary. Regarding the scratches: they look too uniform and blurry in the mid section, it doesnt look realistic. Just keep working on it!
I think some diffusing fog could definitely be used here to add some more "body" to the whole scene. Either fog machine or kicked up dirt. Looks solid though, given the reference.
Yeah I see now that it is definitely to bright, and lacks contrast. Tone down the specular for the coated stuff (I assume that mailbox is coated) use dark colors for the scratches in the diffuse and bright values for those in the specular.
Ah okies, I am indeed using the photoshop plugin. Yeah, would be nice to have the metallic system in there, however I will try and darken my diffuse and see if I get a more metallic look.
Your right. I went back and lowered the spec & changed the diffuse color slightly, not so Lime now. more natural green. (Updated Image above for sake of not having 100 images of the same thing)
Yup what mirbobo said, also if not going for pbr the workflow will be the same as in define material type and colors first then you can go as much in detail as you want on diffuse, gloss, spec, normal etc.