Quote: "How easy is it to get it to work?"
Very. It's built in such a way that it has tons of defaults prepared in advance, so that it's more or less plug and play if you don't want to go through the details.
Quote: "Is the AI any good?"
Value statement. You'll have to define what a "good" AI does as opposed to a "bad" AI. It's much like any software -- DarkAI does what you tells it to. Any "bad" AI in such an equation can only be blamed on the user.
Quote: "How efficient (resource-wise)?"
I think it's fairly efficient. Compared to shaders and other calculation-heavy operations, it's extremely efficient. Then again, they have their own hardware.
It all comes down to how you write your code.