I GM'd this adventure for three players, and it was thoroughly enjoyable for all of us. It is very well done. Although there are a few flaws that a GM needs to be aware of, they are all fairly easily corrected with little fuss.
There are basically two parts to this adventure: the events in the town of Ravengro, which center on investigation, research, and dealing with some spooky occurrances; and a dungeon crawl.
The Ravengro section is interesting and can be quite engaging; however, there can easily be a temptation for the PCs to skip right to the dungeon crawl and miss out on all of this material. The GM will need to come up with some tricks and techniques if he wants to make sure that the PCs experience all of this part of the adventure.
There is an acknowledged problem with the Ravengro Trust system due to editorial errors. However, this can easily be fixed if the GM is willing to make a few minor adaptations, or the Trust system can be discarded altogether without doing much damage to the adventure.
The dungeon crawl portion is exceptionally well done. It is thematically coherent, architecturally logical, and narratively well arranged. All of these things work together to build a believable, immersive experience. The challenge level is high yet reasonable, creating a sense of real danger, but not of any unfairness.
The dungeon's only potential weakness is that it relies heavily on haunts. If the GM or the players do not like haunts, there may need to be some major adjustments. However, the haunts here are appropriate and well-designed, so they are less likely to cause frustration.
This adventure earns four stars easily, nearly five. It is very fun, and the few problems can be easily corrected by a good GM. I highly recommended it.