Here's the automatic difference between his helmet and yours:
Yours is yours. Yours can be placed on your head, and your shelf, and your website, and folks will ask, "wow.. where did you get that?" and you'll say.. "I made it myself."
9-out-of-10 will say "wow.. can you make ME one", or "How much do you want for it?". not.. "yeah, but it sucks 'cuz I saw this OTHER helmet online.."
Every other difference is just an Artistic Interpretation, which is to say, different. Better? worse? nope.. just different.
Better/worse are subjective opinions... "eye of the beholder" and all that.
He essentially copied what he was able to find, using computers, 3d modelling systems and stuff. That's less of art and more of just straight manufacturing. His version also completely ignores a lot of bevels and stuff for some reason.
I'd call his helmet a great starting point, and if ya'll wanted, I could start highlighting areas that are different from the game helmet so you don't do the same thing. His helmet is very useful in giving everyone a sense of what's going on with the game helmet, and excellently made, but it's not perfect.
It's great, but by using it for basic reference we should be able to turn it up a notch.