The file system and localStorage both use plugin-specific storage locations, and the storage policies are the same. In that way there’s no difference between the two (you can see them on disk in sibling folders). localStorage is just better suited for key/value storage, while the file system is more general purpose. If you really need something to be persistent, make sure that you let the user save the data somewhere on their machine. (This could be an export of your preferences, for example, if they are laborious to configure.) As such, if what you’ve got is working for you, there’s no benefit to changing.