> Static types are documentation. Better yet they're documentation that can't go stale without a computer yelling at you that it's wrong.

Absolutely, and I'd go further:

"Most errors, in my experience, are caused by bad architecture, poor documentation, and poor communications strategies between MVC, etc"

Good static types (a la Hindley-Milner) encourage good architecture, serve is documentation that cannot go stale, and encourage good communication strategies between different parts of a codebase.