How did Letterman's show change when it moved to the 11-30 time slot?

How did Letterman's show change when it moved to the 11-30 time slot?

When we went to 11:30, I think it had to be a little slicker. I don't think the show could have been that much about failure, but it had to be about success. You're the cream of the crop, you made the 11:30, you're an upper class man, you can't do freshman stunts anymore without losing the essence of what the show was, or what the star was. You had to balance all that out. You were a flagship for the network now, and to Letterman's credit; he's brilliant at that. He truly knows how to adapt and work and rework. Everyone was taken by surprise by how strong he was at 11:30. There were critics who said they'll never be able to do that show, they'll never succeed, it's too crazy, they'll never be able to do a late night, an 11:30 at night show. He proved everybody wrong for a lot of years.