Our main thrust has been to automate what is generally thought of as production batch processing though we also use it for our full scale integration testing. It has replaced various other scheduling and automation products such as Unix chron, Windows Task Scheduler, SAP Schedule Manager, Mainframe scheduler (JobTrac), etc. Its initial selling point was its cross platform capabilities far exceeded that of other products available at the time.
We have about 130,000 objects and execute about 25,000 process flows a day in our production Client. Within those process flows are about 17,000 file transfers and 50,000 jobs.
We are looking at using it to automate our change management/control process for migrating various kinds of components into the production environment. We are not certain if we will "roll our own" or perhaps use the Application Release Automation (ARA) component.