On my 2 trips to the World we visited 1900 PF both times. The first time we went just as they opened and it was great. The characters seemed to be happy, and interactive. They had fun with my son and were more playful.
On our most recent trip when we went at 10:45, the characters seemed rushed and already tired/annoyed. Eventhough we had 2 younger kids with us, they zoomed past and didn't take any time to have the kids have fun with them.
I understand that they have things to do, but we didn't get half of the autographs the kids wanted, eventhough we had the book right at the end of the table so it was ready.
If we go next year it will definitely be an earlier ADR.