I'll start out by saying the expert class Monster Slayer is a very useful class when you need to take out a monster (as opposed to a humanoid enemy). Some of his abilities are truly exceptional, especially in Dramatic scenes. You can generally sum this class up as somewhat like a Ranger focused on monsters like dragons, though that isn't a prefect comparison.
My only complaint is that the three feats at the end are NPC only, unlike the other two classes that were put out at the same time, though it is a small gripe as the upper level class abilities are really nice already.
[5 of 5 Stars!]