When I got mine I only showed the FSDO the sign-off record I had kept in the back of my logbook. I had a separate sheet of paper with all the dates and results of my students checkrides but the guy looked at me with a "settle down boy" look and told me that was enough. Because three of my student's checkrides had taken place in the past week they didn't show up on their computer record, but he said he'd take my word for it. I think the documentation required depends on the person you speak with.
What did I get out of it? Besides a little bit of professional pride, when I went for my first airline interview and handed over all my certificates the interviewer said, "Ooooo... Gold seal!" in a somewhat joking tone.
It certainly did not hurt, though...