Mule ESB provides a standard integration framework that makes system integration simple. It allows for faster and more robust integration through various connectors that facilitate data transformation and exchange across formats and protocols. Some key advantages of Mule ESB include being able to easily create and test flows in a graphical drag-and-drop environment without extensive configuration knowledge. In comparison, Spring Integration takes a more application-centric approach best suited to small-scale internal integration, while Mule ESB acts as a full integration platform suitable for a wider range of scenarios.