Is there a way to use File Field but have it’s directory path be different for different instances of content, instead of the same?
You can define your file paths with node tokens. File (Field) Paths module provides the functionality that you are looking for.


  The File (Field) Paths module extends the default functionality of
  Drupal's core File module, Image module and many other File upload
  modules, by adding the ability to use entity based tokens in
  destination paths and file names.