SJ + Hot Toys Black Widow side by side
First thoughts. Black roots are absent. Eye's could use more blue / green
Hair style possibly too rounded, polished. Head sculpt might look better slightly narrower.
Hot Toys could have improved the outfit, if they had dropped the large silver zipper, as
it is not such an obvious feature of the original.
Moving further down, looking at Black Widows legs, they appear to be on the thin side.
Based on the images shown so far, i rate Black Widow 7/10
From what has been shown so far in the Infinity War line, the other characters look better.
The bottom line is, Black Widow Infinity War fails to be between the eyes, like Hot Toys Princes Liea Hoth, to name one example of Hot Toys on form