Finally I cleared the
SCJP 6.0 with 88%...
I took 3 months to take the exam... I read K&B twice, first intensively and the last focusing on the weak points... read some tips at javaranch and all over the internet...
did all the 5 whizlabs' exams and the average score was 77%...
I think is enough to pass the exam... My exam was very easy, it was easier than the whizlabs exams.