Hi Chris,
Categories are a default option in Filter Bar, and additional fields are added as options when you create the fields. So, you can really use both or either one. You can see a demo of Filter Bar over on wpshindig.com. Categories do have their own pages that display all upcoming events for that category, so if you would like to use these pages for anything, this might be the way to go.
We do offer full refunds within 30 days of purchase, so if you’d like to take Filter Bar for a test run, feel free to do so! Please let me know if you have any additional questions.
Thanks,
Jennifer