Exploration/Puzzle aspect was pretty well done and definitely appreciated by the players. It dragged slightly at a few points but that may have just been these particular characters and their interests. The players suspected the wrong person for quite awhile and were pretty happy when they figured it out. The final battle was a blast to DM and the players were scared for their lives. They defeated the creature without too many permanent scars.
I'd recommend. Combats were interesting and each one challenged the players in a different way. The final combat was especially interesting and they did not expect the lair actions. The storyline was memorable and they really seemed to enjoy figuring out who took the books and why.
[5 of 5 Stars!]