An excellent dungeon crawl. Very challenging, especially for level 1 and 2 characters. Even scaled-down, it's a lot of encounters for those characters.
The mystery that opens it up can be a bit tricky to unwind, but most of the stops have clear clues to spur you towards the plot. It can bog the game down if there are completionists in the party, though. The first fight and its revelations are very interesting, so there is some payoff to the investigation.
Probably the biggest problem with this module is that the most interesting part of the story is all behind the scenes, and the players don't really get to understand the interesting backstory of their antagonist and what motivates the goblin forces. More explicit hints as to what's going on than vague descriptions of a horned goblin and other goblins pounding spikes into their heads to look like him would really help the adventurers get interested in their foe.
[5 of 5 Stars!]