Ultimately it is entirely about your own implementation details. You need to consider who you are developing for.

The concept can be implemented entirely in code with switch statements or similar branches, entirely in data with everything configured externally, and anything imaginable in between.

The…

I created a behavior tree system that is defined completely within c++.  

AI entities have a brain which spins up a behavior tree.

The nodes in the behavior tree are heap allocated, which I believe does have some noticeable performance cost.

The reason for this was to easily use virtual methods a…

I ended up with using Behavior Trees as actualization process only, I calculate the AI's decisions using Utility-esque process.

I agree with @frob statements of the Behavior Tree not being a swiss knife, the reference I've posted sums it up pretty well - it's a good tool but many times used wrongly/…