Hi,
One of the biggest drawbacks of EJB is that it is very difficult to test EJB components separately from the EJB container.Spring provides a well-defined class hierarchy for the EJB support classes.Implementing EJBs with Spring is not drastically different from implementing EJBs using traditional approaches. However, Spring support makes it simple to factor out the implementation of your EJBs into a POJO class, thus reducing the barriers to testing and helping you deliver quality software.Now all majority of new projects are in Spring Framework compare to EJB project.In some company,ie GE..planning to convert EJB to Spring + Hibernate.So for new comers in EJB,he can choose,wheather he study or not EJB3 or Spring+Hibernate.
If you are going to maintence project,,you must study EJB..Because majority of old projects are in EJB..that is all.:-)ie Universal Truth.:-)
If you have doubt..First Study and do the project in both EJB and Spring+Hibernate.Then you can decide which is better.?Your final answer may depends on your view point and your project nature.
Thanks&Regards
Joby