Both Chris Lema and Pippin Williamson have written fairly detailed reviews of page builders. While I do not plan to replicate their work, I want to comment on an issue I ran into with the Visual Composer plugin.

Visual Composer is quite developer friendly, so that developers may add custom features and layouts that enhance a particular project. However, the customizations along with the plugin itself, are often bundled as part of a theme. As long as the theme developer keeps the theme and plugin up-to-date, this does not pose a serious problem. If the theme is no longer actively supported, both the plugin and the customizations can start causing trouble.

Using an old version of Visual Composer may cause JavaScript errors and/or become incompatible with other plugins. Of course, the remedy for having an old plugin installed is to update that plugin to the latest version. Updating Visual Composer can bring up the second issue where the API for customizations has changed, so that the custom features fail to work. This can cause items not to save correctly. A specific example that I encountered is that both background images and background videos disappeared!

While a developer can fix the issues and get everything working again, this does not make for a very good user experience.