I used behavior tree to create a smart Minotaur AI which can;
• Hear, see and predict using the perception system
• Unlock abilities by completing side-objectives such as destroying statues, killing NPCs...
• Use abilities properly like a human would
• Roam the labyrinth in a natural way, without backtracking too much, with the help of EQS
Behavior tree of the Minotaur AI
I also have some experience using the new state tree system as I am using it on my current project.