I spent today researching DRF serializers and have discovered that they're easy to use and excellent for direct-to-model, CRUD-style interactions via an API.  However, because the current API in many cases is combining fields from multiple models and objects, it's not very straightforward to work with the serializers -- especially when it comes to managing optional fields which are not present in the actual model fields (eg, an error message element).

Tom Christie mentions using a custom serializer field to achieve the optional field outcome (http://stackoverflow.com/questions/17552380/django-rest-framework-serializing-optional-fields), but it seems like overkill just to be able to use the serializers instead of working directly with the request/response data.

So, I'd prefer to leave this particular aspect of the PR as-is for now, and we can work on evolving it as we learn more about DRF going forward.