All business logic is in the database itself. It has ACL's and data validation built into one feature (update validation) and as for deciding which data to disp

All business logic is in the database itself. It has ACL's and data validation built into one feature (update validation) and as for deciding which data to display and when, the map/reduce-based view API is extremely powerful. Force yourself to use CouchDB for a project where you're handling large amounts of data and you'll discover how incredible it really is. There's tons of other great features you'l pick up along the way too.