Powerful Configuration, but was Inconsistent
We implemented this to support a SharePoint application that was built before we started using the workflow capabilities. It was easy to setup, and we found the customization very powerful, but it frequently stopped working and the logs even at full sensitivity couldn't tell us why all of the changes/events were being ignored.
Even though we purchased support, we received very little help and no definitive fix. We eventually stopped using it since the users couldn't depend on it.