It replaced cURL for me

As a web app developer a tool like this is essential. This is the first one I’ve tried that can take the place of cURL in my toolbox. The ability to easily set headers, form values, and do authentication is much easier to use than cURL. You can also save configurations, which helps with testing.

The UI is a little strange—I was confused when I couldn’t find a “submit” button. Instead, you click the “Response” tab/button and your request is automatically submitted, showing you the response. (Or: ⌘-1 for Request, ⌘-2 for Response, which is burned into my memory now).

natevancouver about RESTed - Simple HTTP Requests