Sometimes you need to look at a previous version of a page, or article. Sometimes you want to restore a previous version. Joomla supports this with versioning the article, and offering look at , compar, and restore previous versions.
I am missing this in SP PB. I understand it has the export /import feature, but this is not the same. Importing a previously exported page creates a new page with a new intrenal ID. All links would need to be updated.
Yes, you can import from within the editor of a page using the layers, but again this in not the same. Much work to do. And there is no easy way to simpy have a quick look at how a page looked, say, two vresion ago, without restoring that version.