I passed the exam with only four wrong out of 60. The four was spread out amongst 4 different sections, so there was no particular area I was really bad in. I had used lots of my preparationtime to learn the ins and outs of Formatter/System.out.printf/PrintWriter.printf, but got no questions about that.
I have 10 years experience in java programming, and have spent about 10 hours/week for 2 months preparing for the exam.
I read the book SCJP Study Guide by Kathy Sierra and Bert Bates 3 times, took all the included mock exams and quizes two times.
I also took the complete set of tests in Examlab for SCJP 6 by M.Devaka Cooray.
Finally I practiced by doing various random mock tests.
I used about 30 minutes on the first pass, finishing off the easy questions,
was really upset when only 10 questions was answered, used about 60 minutes on the middle/hard questions, and another 60 minutes on the final 5 ugly questions.
Then I took 30 minutes to go over the exam one final time before pressing the dreaded "end" button.
I think the questions I got on the test was hard, and I had to really think what the correct answer(s) was at about 60% of the questions.