Was looking for something to search through all my documents and get rid of characters that my NAS backup drive didn't like. I gave up on Automator and tried Renamer4Mac, which was OK, but this seems better. First, it has a good clear preview option which allows you to selectively accept or reject changes. Second it has an undo in case you screw up. Third it's very fast on search. And last, you can set up multiple search criteria easily and save them as one search. (I think Renamer can do this too.) Very light help manual, but hey it's free!