I was a bit puzzled that Red Shroud had the Fatespinner prestige class, but then I realized that it's supposed to represent her membership in the Fated faction. Nice touch! I was glad to see Fall-From-Grace name-dropped, too.
On a quick read-through, the adventure is very atmospheric and varied and I love the additional detail on the Abyss and its prisoners. The detail on Ahazu and his cult really makes the Wells of Darkness come alive. However, the whole thing seems - again, on a quick read-through - to be pretty anticlimatic. The PCs have to go through all that just to be told... well, no need for spoilers, but it seems rather sadistic if I'm not missing anything.