Spring vs EJB3

Iam posting this topic since I have experienced this topic being raised during one of my technological architectural level discussions I had with my collegue and basically he was supporting EJB3 and me,Spring...And I leave it to you guys who are ready to post their own comments and reason out with pros and cons which technology is better to use in mission critical enterprise level J2EE applications and share your experience and thoughts.........

For now Iam directing you to this link and if you have any other resources/stuff do post in here........

SPRING V/S EJB3

Managing Applications With Java SE 6: A Conversation With Vasanthan Dasan

As Java technology developers write more complex and sophisticated mission-critical programs, the need for improved monitoring and management capacities in the Java platform has also grown. Java Platform, Standard Edition 6 (Java SE 6) now enables developers to attach command-line utility diagnostic tools such as jstat, jmap, jhat, and jstack to any application without requiring startup in a special mode. In addition, JConsole, with enhanced plug-in support and dynamic attach capability, is much improved.

http://java.sun.com/developer/technicalArticles/Interviews/dasan_qa.html?feed=JSC