Hi,
The specs is more important since it covers the entire scope of the exam.
Use the book to clarify any concepts that you are not clear in the specs. I've spent 4 consecutive days in studying the specs - helps me a lot for the exam as the stuff are still fresh in my mind.
If you are running out of time, I can suggest that you may wish to skip MDB and security stuff (at your own risk!) and concentrate heavily on session and entity beans (especially those in the specs), transactions (BMT & CMT) and EJB-QL.
Hope that helps
