Oh yes, wasn't it fascinating?
It's difficult to know what to say about it, isn't it? I found the science regarding his Alzheimers riveting, but it was also so emotional and heart rending, not only for him, but for the people he encountered.
I found myself sympathetic to the candid admission from the daughter of a fellow PCA sufferer that she had a momentary "Yes!" moment when TP revealed his condition, knowing it would bring publicity, money and research in a way that a non celebrity sufferer couldn't.
I found Mr Pratchett to be a really thoughtful and intelligent man, but he lacked any cloying piety thank goodness! As he says of his PCA himself; it's an 'embuggerance'!