Hi Keith,
Sorry that I could not reply ealier. I just cleared part I with 93%.
I used step1 from Arc2Patterns, I could not answer your question without actually taking the
test and getting a feeling of its materials compared with actual test :-)
Now that I took the test and passed it, I can say its materials is good, probably sufficient to pass, but if you need a good score, I think reading the EJB spec is essential.
There are some typos, duplicates, grammar errors together with a very small number of wrong answers (confirmed from its support team). But honestly speaking, I could not persuade myself to agree with some (small number of) answers it provided to some real hard questions, fortunately,the actual test seems a bit easier and always give you the hint on how many answers should be selected.
Overall, Step1 from Arc2Patterns is good, par with the exam's objective and difficulty level (a bit higher in Arc2Patterns).
Remember reading the EJB Spec!
Cheers,