Purchased the hardcover book earlier in the year and thus far have gotten a good amount use out of it, especially on the side of Monsters.
I enjoy the feel of the non-glossy pages, but I will admit that one should practice caution on those late night planning sessions.
I've spilled plenty a characterising stain on DM Guide and Monster Manual but yet as of yet my GM Toolkit is safe! Can't imagine the material will play nice with water!
The puzzles are great, and stump even some of my more savvy players!
Even loaned my copy to a fellow DM as he was in love with 'What's In A Name'.
I've still yet to run the one-shot dungeons, but on paper they all look great! But I did re-tool the alchemist scenario into a Vampire/Drug Den and it worked woderfully in a city setting!
Everything is well documented organized and structured, and it's easy to find what you're looking for.
It also came with a PDF!!
There was a glaring printing error in my copy as the first few pages were from a book on Native American history, though this is likely the fault of the publisher, not the author.
Several spelling errors and other grammatical issues, not a huge issue if you're not a stickler for that kind of things.
If I could buy it again with no errors of any kind? I would probably do so.