Alport - yes Joan did have to send one of her certified trainers to speak on her behalf at APC two years in a row. The first year it was due to her own emergency surgery and the second consecutive year it was her husband who was having surgery (at the time he was diagnosed with pancreatic cancer).
At one of the conferences a few years ago I was set to attend one Joan's sessions. Due to some circumstance, she was unable to attend and had one her staff do the session. I don't remember if was the APC or IAAP. Either way I have attended both their conferences, this year I am going to try and attend Joan's. Hopefully the budget will be there.
I have read both Joan's books and highly recommend both. The are a must have for any admin who wants to be successful. Even if you are a season veteran in that inner circle they are both great books to refresh and revive your abilities and thoughts on the profession.