Blog post by guest author Cannon Smith, a 4D developer from southern Alberta, Canada: 

The introduction of collections and entities has dramatically changed the landscape in 4D, giving developers new ways to map business rules to code. Just recently I refactored several thousand lines of code that were central to the business rules of our application, resulting in a significant speed improvement (5xs faster) which our users are very happy about. This refactoring was largely about moving from old code constructs to objects, collections, and ORDA.