looks like a good start. Only thing that jumps out is the snout, the snout on the one in the picture looked much more P2ish, where this one looks more P1ish, my only criticism thus far. Looks the part though, i was actually thinking of doing this one for quite some time but figured someone would beat me to it so i didn't bother, lol.
That's lookin' badass, Casey! Truly the helmet master. I really like that you posted progress pics, too. You can't beat an artist that's willing to share the progress of a piece from start to finish. I will for certain keep checking up on this as you progress. If it's any indication of your previous work, it's gonna be a bad-ass representation!
Two thumbs up!
On a sidenote about the general design of the helmet, I think it's a little too much fanboy-ish. Nothing to do with Casey at all, just about the design of the bio itself.