More than ChatGPT, it's optimized for development with custom actions such as "Edit Code" that provide you with a diff you can refine. Also, you can create your own custom prompts and that's cool.
This VS Code extension is incredibly user-friendly and provides a range of powerful coding features. The ability to edit code using AI and view the resulting differences is a game-changer. Simply select the code you want to modify, provide a prompt (such as "please refactor this into two functions"), and observe the resulting changes. In my opinion, it's a significant improvement over Codex, and it's also open-source.