I'd put "overrated" in the same category with "long-awaited." It makes me want to ask "long-awaited" by whom?

The word is currently being used for Britney Spears' "long-awaited" memoir, which has just come out. But that one wasn't "long-awaited" by me.

I do use overrated, sparingly, but never for a new book or movie in the context you mention: only for bestsellers that have been out for a while and had vast attention. Even then, I'm careful to say what, exactly, is overrated about and not to use "overrated" as a throwaway term.