This was an excellent module to run, overall. The scenario is full of intrigue and was easy to adapt to a homebrew setting. I would only caution DMs to be extra wary with lower level parties.
I ran this for my party of five level five PC's, who are generally tougher than average. Having found that the total XP of the encounters well exceeded their daily threshhold, however, I made a number of changes. Both bosses I adjusted down to CR 9, including reducing the health more than suggested, and lowering the damage output for the wight significantly. I also removed the eels and made the hag friendly by default. Even with the changes and the dice on their side, the party ended up within a round of wiping. This was great for the tension, but relying solely on the APL guidelines would have led to drastically different session results.
The biggest change I would suggest to anyone running it regardless of level is to rework Sandy's initial response to the party. Players are generally not prone to deescalation, even when presented with the opportunity. So I would instead have her respond with frightened surprise or an attempt to hide rather than open hostility. This gives the party a better chance to get information out of her, and still affords to ability for a fight to break out.
[4 of 5 Stars!]