Just joined, been a level 3 for about 8 years, trying to get an idea where I stand with the level 4. I rushed through the test in 20 minutes because I wanted a quick snapshot of how much I will need to study and passed with 71%. So, probably a combination of field experience and luck helped me pass with '1% wasted effort'. Seems like it will be useful to record the questions that I get wrong and then use that as a study guide. No point trying to just answer those specific questions, best to dig into the subject and be ready for more similar questions later. It would be good to receive an email containing failed questions complete with the multiple choice answers for those questions.
Great site, thank you.