How is using the Developer Edition of Salesforce with VerticalResponse different than other versions of Salesforce?

When using the Developer edition you will still receive the same great options that all Salesforce users get when using the VerticalResponse app.  The only difference is that you'll get access to the Developer console, which console allows you to edit and debug your source code, view debug logs, analyze performance, run tests, and execute SOQL queries. Pretty neat, right?