I haven't gone through EJB 3 in Action and have not purchased Enthuware exams but, here's my input.
I thoroughly went through the O'reilly book, MZ notes, and took the Sun's free sample exam before taking the actual exam. And guess what....I failed. Got 49%, where 59% was required to pass. The LEAST EXPECTED OPTION IS CORRECT ANSWER MOST TIMES.
I did not go through the specs assuming that what I read was enough, especially after considering the fact that the specs were close to 1000 pages.
I was a bit disappointed but, said to myself that I need more preparation.
My experience after the actual exam is, SPECS are a MUST. Both CORE and PERSISTENCE.
I'm not giving it up. I have my retake scheduled tomorrow. Will let you know after I take it.
All the best to all test takers.