I use it along with some Apple Script to automate the process of scanning the two sides of a check to be deposited, OCRing the scans, naming the files so they can be identified, and moving the scans to a folder for the current month of the current year. There are other ways I could do that, but my Automator + Apple Script workflow reduces it to a single step for me. I have other workflows that I use on occasion, mostly to organize and move files or scans. I have even replaced one or two simple (and I mean SIMPLE) app store apps with workflows. Not that the apps were not doing the job, more that it was an interesting exercise to create the workflow and in one case the app that was replaced simply did not do everything I wanted it to.
I could live without Automator and not miss it, but I use several third party utilities that are based on Apple Script that I find invaluable. I keep telling myself that one of these days I am going to have to get serious about learning Apple Script and creating my own utilities.