Once your suite reaches a certain level of complexity, you will probably want to start testing features from different states. This is boss-level regression testing.
For example, let's say one of your features lets your users add a widget to their account dashboard. Now let's say only users with admin permissions are able to add a widget. For comprehensive coverage, you should be testing both states.
To do this, you'll want to add a 'login as admin' step variable in addition to your 'login' step variable that already exists (to stick with our example). The work on your side is creating a bunch of test logins with the correct admin state enabled and uploading this to your Rainforest account.