There was a vendor selling the Morton/Paul book at the National Exhibition. I spent a few minutes browsing it, but was not persuaded that it was worth buying. The fact that Mr Morton does not seem to have any bonsai of his own worth showing (as noted by Scott) is definitely a red flag in my opinion.
As for the photos, most of Walter's trees can be found for free on his website (and I think those images are at least as good in quality as the ones in the book), so that's not really a compelling reason to purchase...
Side note, does anyone here subscribe to Bonsai Focus? If so, what do you think of it?