Pros:

1. Part one is essentially an excellently written story hook for part two.
2. Part two is flavourful and just scary enough - there are also several ways of going about this that make the scenario decently replayable.

Cons:

1. The actual beginning adventure hooks need a bit of creative license to make them work for the more considered and cautious adventurers, though doing so can pay off later.
2. The boss is fleetingly scary, though is intelligent, has minions, and can become actually scary if the party manages to back themselves into a corner in the mines. To avoid disastrous circumstances, it may be wise to drop hints about the number of exits to a room, and so on.