This is an excellent, well written module. It fits well in a 4 hour slot, the characters are interesting and give a DM room for role play (or not, if you're not into that), and there is a variety to the combat. I really enjoyed the four different possible outcomes for the end. There are clues that point towards getting the best ending and it's really up to the players to solve it.
If you're running this module, the only change I recommend is removing all references to the temple before talking to the NPCs. My players didn't see a reason to talk to the NPCs when they knew that the missing NPC was last seen at the temple.