This adventure is a mystery and the villain is part of a larger series, so I think it has to be reviewed a bit differently than other mods. Players won't get to the final destination in this adventure. The question is whether they will enjoy the journey. At my tables, both as a DM and a player, the answer was a resounding yes! There are a lot of NPCs, and most of them are fun to play. Just bring a cheat sheet for your players. The combat encounters are challenging and unexpected. Players may even encounter a bull in a china shop! Randomization of the central whodoneit adds replay value. Not being able to resolve the entire plotline is frustrating but didn't take that much away from my players' experience.
One important caveat about this adventure...it is a mystery that requires players (not their characters) to know how to ask the right questions to get better clues. This isn't a skill that D&D players use all that often, so they get frustrated and blame the mod. What makes this mod a unique pleasure for some groups I DM for will not appeal to others.
[5 of 5 Stars!]