Putting the figure next to the cartoon model just shows how good the engineering really is. But now I wish his head was a little bit bigger
As discussed here, there are two main helmet types for Ironhide and Ratchet in the cartoon. I personally would've preferred the thicker one for Ironhide and thinner one for Ratchet, but they've evidently chosen to go for the thinner style for both Ironhide and Ratchet.