You needn't have any agent-written code in your apps, but its auditing and bug-finding capabilities are worth the price alone. I pointed Codex at @takeoneapp and in seconds found an obscure layout crasher and a datastore object orphan bug. I did all the fixing, but it talked me through why my logic was wrong.

I do wonder what that alone could achieve in a 'Snow Leopard' OS release, where every last project in the system gets a 'free' audit the likes of which it probably hasn't had in 30 years