As a reply to my own msg, but to maybe help others out who have this question, here is the answer:
We went to the bfast on Oct 20 and had a great time! The food was good and the characters were great! We saw Elmo, Cookie Monster, Bert, Ernie, Zoe, Count, Abby and Big Bird. Everyone but Big Bird came to the tables (he's too big and would run over the kids). You go to the stage to see Big Bird. They did some songs and dances on the stage too. The morning we went, there were only about 10 families there so it was uncrowded and not rushed since they do two sittings instead of constant reservations.
All but Big Bird signed our book but they had a bit of trouble doing it. I think we were the only ones there with a book. Would recommend a Sharpie or big marker. Their hands are a large and hairy so it is not easy for them and I don't think they do it often.
My DD was ok that Big Bird didn't sign. She took a page and signed for him, which was her idea but I think a great way to reconcile the ones that don't sign besides just saying they don't know how to write. I'm going to get her to "sign" a page for King Louie too.
HTH!