I was looking for a universal directory component to able to construct (almost) all of my sites.
This has everything I wanted, multiple content types, flexible templating system, very flexible fields, multiple categories per item, etc., and Excellent access control if you combine it with FlexiAccess (I had a little trouble with it but I resolved, please read documentation for FlexiAccess although not complete).
The big bonus is that your content and categories etc are inserted to the standard Joomla tables, only the extra information about fields, etc., is stored in other DB tables.
It is an excellent directory component for the end user, and something a developer would love to use.
I hope I will be able to actively be involved in this component.