I just passed the exam 3 hours ago
I have been reading like a mad all weekend and taking mock exams. I only had time to take the first two Devaka exams and scored just below 40% on both. On the K&B MasterExam I only scored 44% (I took it really fast and the lacking information about how many answers to pick properly lowered that score quite a bit).
However I carefully analyzed the questions I got wrong, and quickly wrote small programs to memorize it better.
I personally think the exam was quite a bit easier than both Devaka and K&B MasterExam - there were less traps, and I think I spottede most of the traps based on experience - especially from the Devaka mocks.
I scored 73% on the real exam - which of course is not near perfect, but more than enough to pass
So if you score 88% on the MasterExam I think you are ready. Just remember to get a good nights sleep before the exam, read every question carefully and stay calm. I personally used every minute available