Seconded. I always write a summary even though many writers don't, and my emphasis on summaries is also to define my client before a junior recruiter or inexperienced screener does it incorrectly on their own.
I hate the "objective statement" (since it is almost always just filler nonsense), but a good personal statement can go a long way. It's like a good thesis statement: make a bold claim that is backed up by the evidence in the resume. But it helps to tell people what unique stuff they should look for.