We were approached recently by guys from MalCare that were interested in getting a review article for their service. As for you that do not know MalCare is a new service that protects WordPress sites from malicious attacks and cleans them out in case that they were already infected. We made couple of tests on our server and here is what we came up with.
By definition staging is an environment for final testing immediately prior to deploying to production and it is meant to mimic production environment as closely as possible. Best practice is to create a separate server for your staging environment. What this plugin does is that it creates a staging site in a subfolder of the live site and copies all live database tables with a new prefix in a same production database. There are a lot of things that could go wrong if you are making staging site in this way.