seems like the closer your reservation is to the most popular dining times, the worse the back-up. We're early birds at all meals - worst we ever waited was 15 minutes at Coral Reef lunch in January (was a 11:50 lunch ADR.) At Chef Mickey's breakfast in January, we had 7:30 a.m. (our choice) -- we checked in at 7:25, and were seated at about 7:35. There were maybe 6-8 other people waiting at that point.
When we left about 50 minutes later - close to 8:30, there had to be 75 people waiting & a steady stream of people walking towards the place. It was obvious the later breakfast times were much more crowded, and the seating was backing up. Can't imagine what the crowd would be like by 9:00 a.m.