I sure that most people would think that getting a 90% on the OCA 808 exam is a good thing (and I agree). However how much better is get a 90% (or some higher number) then getting 66%. In the end both 66% and 90% are passing grades and the 90% does mean that you have a really through knowledge of
Java.
However that 90% could also mean that you got lucky with the exam, every has the one or more area where they are weak. They could be week with regards to lamdas or predicates or some other are and if there are many questions in these week spots then the person who got 66% may have gotten unlucky. Currently the OCA exam is 70 questions, so each question is worth about 1.4% and the person that achieved 90% answered 63 questions correctly. Where as the person who achieved 66% answered 46 questions correctly.
On your resume, Linked In, Monster, or other, would you say that you got XX% when you passed the exam or would you state that you achieved certification? On one hand it may look like you are bragging and many people do not like it when other people brag. Yet on the other hand the person who got 90% may have earned the right to brag a bit about their mark.
Still when it comes down to it and you are applying for a job at Company XZY does showing that you got 90% mean that you are that much better at Java programming the someone who got 85%. Does it really matter that much? I mean when you start working for Company XZY they usually don't really care too much about your mark on the exam as long as you can produce the results that they want/need in the time-frame specified.
BTY: I'm currently preparing to take the 808 OCA exam and I'd like to get 90% or better, however that does not mean that I will.