1) A whole lotta white space going on here; I really would not have minded a smaller page count in exchange for a tighter layout (even sans the encounters; they're cool, but man, I dunno if I'll ever use any?).
2) No monsters by terrain type?!? Ahem, from http://www.talesofthefroggod.com/index.php/products/the-tome-of-horrors "... and plenty of charts dividing the compiled monsters by CR, type, and terrain...."; with my other monster books I use the monster by terrain listings as encounter tables (by penciling in the #s on a printout of the pdf), and I assure you, I would have gladly exchanged the encounters for some terrain tables, or especially encounter tables by terrain.
It's still a cool & bad-ass monster book, but man, I was really looking forward for there being charts by terrain type for my over the top obsessive encounter tables. ...unless I missed the terrain charts on my first breeze through the pdf?
EDIT: If you preordered it and can't find the PDF on the download site, try checking the "ezine subscriptions" section instead of PDF downloads when you log in.