It provides very good support for data quality, consistency checks. The UI could be more user friendly especially when working with complex queries/rules which require multiple conditions to evaluate (i.e., many ANDs). As mentioned above it's not really easy to use as compared to other products out there in this area of interest, so I would say that you should check if those features are important enough for your needs before choosing CEF. We needed something integrated into our CMS system providing some kind of preprocessing step for content items being added or edited within, but also allowing users to execute custom scripts during their work flow process. This tool turned up right away and has been helping us managing quite complicated requirements including validation processes.