I've just finished listening to this on radio 4. It was adapted to take the place of the afternoon play for a week. Five instalments of 45 minutes - over three and a half hours of airtime to tell the story.
Now I haven't read the book, though I have enjoyed Irving in the past (I'm not great with modern US novels - Updike put me off). I've read Cider House Rules and Garp, and I was lucky enough to see the mad film adaptation of Hotel New Hampshire with Nastassia Kinski as a bear (well, sort of - like most of Iriving, it'd take a long time to explain).
I've listened through the plays, albeit at work, so subject to the occasional interruption, and I confess I didn't understand.
I knew I liked it. It was well dramatised and acted. And I knew it was a complex story. But the last half hour left me resolved that I'm going to have to get the book if I'm to have a clue at all.