I've got two words for this model: Epic Win. The only thing i could think of to improve this would be to use a smoothing method like what macattack64 did to Belakor's H3 Recon helmet, and probably just for the top part to lessen the amount of Bondo needed.
I think the next model you should make is the JFO helmet. Currently I don't know of an actual file being modeled of that, and it is a pretty sick helmet.