I have not heard of a mock that is truly bad, but I must show off that many people have said mine are really quite good, all questions are on topics that can come up in the real exam.
Also part of the revision of Bill Brogdens Exam Prep book I worked on was to indicate which items do and do not come up on the exam.
Marcus
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Java 2 Exam Prep, 2nd Edition by Bill Brogden and Marcus Green
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