My current project involves entering a large number of pieces of data into a series of userforms, which populate fields and select certain content. I would like to hedge myself against the client asking at a later date for the ability to update a completed document (or to pull data from an older version into a newer version). To do this, I would like to store all of the user-entered values in the document.

Are there any down sides to using Document Variables vs CustomDocumentProperties? I have used Custom Properties in PowerPoint in the past, but have not used either in Word yet. I know that the custom properties are viewable by the user, so I would prefer to use variables, but are there any issues that I need to know about?