I have passed PSPO II certification last week. It was a logically follow up for PSPO I certification I did two weeks ago. The main goal was to verify what I learned and provide a clear message that I can think and act as a product owner, which I think is a huge added value for a developer.
I am prepping for the Professional Scrum Developer exam now, but I am still considering going for PSPO III. The main issue I have is the price of the exam combined with its difficulty. It is easy to select value(s) from multiple options compared to writing essays under time pressure in foreign language on expert level. I think I posses the knowledge required for this exam, I just don't think I am able to pass the test.