Recently I secured 95% in the PSMI exam and decided to contribute to the forum for my experience. Hope some future prospectors will benefit from it. I have no related REAL world experience (unfortunately) so far, but trying to get into it, if my luck rides the high horse soon. Neverthless, after passing the PMI-ACP I am a certified PSM as well :) so the journey continues.
1) Having PMI-ACP before, I was not new to SCRUM, but to be honest, after preparing for 3 weeks (6-8 hours a week) I found that the ACP material was lacking a lot of interesting detail about SCRUM which I was glad I covered in this exam, mostly because ACP covers all of them SCRUM, XP, DSDM etc.
2) SCRUM guide reading multiple times to completely understand and comprehend the idea behind is the first and foremost stuff. It is to the point and develops your foundationfor what is coming your way.
3) The USD 10 I spent on buying "scrum narrative and psm exam guide" by Mohammed Musthafa Soukath Ali was a good investment as it covered a lot of hidden gaps which were left for the readers of SCRUM guide to explore and discover. The quizzes and explanations of the answers included were good to give more insight and 10-15 similar questions from it were answered by me in the actual exam.
4) Securing 100% multiple times in at least PSMI and Product owner ones is a must as there were similar 10-15 questions in the actual exam. I did took the developer and nexus ones too to secure >90% (read nexu guide), but I didnt see any question from Nexus part to say the least in the real exam.
5) Last but not the least the forum discussions about the PSM related questions proved to be fruitfull, first to understand the SCRUM better from real world guys, secondly to polish the concept and third for sure at least 10 questions I saw from these forum in the real exam. So hats off to all the contributers.
End note: The exam time window is quite adequate, as mentioned in forum a lot, I ran through all the questions in 35 minutes with the ones I was 100% sure unmarked and marking around 20 questions
which I wasnt too sure about. So later it gave me 25 minutes to open book, google and think deeply about the left over.