Static types are more than syntactic sugar, they allow you to make additional guarantees about the behavior of the code, like having unit tests without actually writing them.

I program in php every day and miss static typing (as opt-in mechanism). Sadly i'm on windows and use oracle, so hhvm is not applicable.

We are just beginning to use the static type information that Hack provides to yield performance optimizations, and that's definitely on the cards as something we'd like to push further.