I passed the exam yesterday with 83%. The exam is tougher than I expected. I say that because some concept that I think I throughfully understand is proved not the case in the exam. You can say the questions are tricky, but if one can throughfully understand the fundamental concept of each topic, you will be no problem.
Questions about thread are tough, be careful about synthronized method. For java.lang, you better know every method under Math class because you never know which tiny method they'll ask you. java.awt questions are straightforward, just take care about how layout manager take effect when resizing. java.io is in the same case of java.lang, got to remember all their methods. For overloading, overriding, runtime type and object orientations, you got to know the concept very very clear!! The same is for declarations and access control. I only had one question on garbage collection, so I think if you don't have enough time for studying, you can giveup this topics.
During the exam, don't be too nervous. If you're not sure about the question, just mark it and revist it later. When you revist it, you're already claim down and have a clearer mind. I marked about 25 questions after the first round, and 3 questions after the second round.
Hope this can help. And thanks for all your help too.