Concerning the thickness of fantasy novels
When I'd mentioned 400k to him once, he'd been wary. He explained to me that he felt 400k was unprintably large in today's publishing market. Things have changed since the 90's, and booksellers are increasingly frustrated with the fantasy genre, which tends to take up a lot of shelf space with very few books. There is constant pressure from the big chain bookstores to keep things smaller and thinner.
I like these "behind-the-scenes" anecdotes, that shed unaccustomed light onto the dark corners of otherwise rather familiar-feeling businesses.
For what it's worth, I've never read any of the Wheel of Time books, but I'm becoming a bit of a Sanderson fan - I really liked Mistborn and Elantris, though the second Mistborn seemed to be phoning it in.