Data Mapper aims to be a better alternative to adding private data via the Folder element. A disadvantage to adding private data in Switch via the normal way is that when you want to use the stored private data you have to remember the exact name of the private data tag.
When you don’t know the exact tag name you have to:
This problem doesn’t happen when using Data Mapper to store data in a job. Data Mapper stores the data in an XML dataset with a fixed structure. When building a Switch variable based on an XML dataset (and having a sample job), you can see the contents of the XML dataset, avoiding the need to copy paste the tag name.