Several days ago I've passed Spring Professional 5.0 certification without attending an expensive course.
Want to thank everyone who shared experience and valuable links related to this and prior versions of certification exam.
In case someone is looking forward to take this certification exam here are some advices:
1. Official study guide is essentialy everything that you need to know to pass the certification. It can be found on the Pivotal certification page
2. There's a software developer whos name is Ivan Kriszan who has already answered all of these questions and published a book (this book covers official study guide questions). Here's his blog
where you can find some useful info (he actually took a certification course and shared his experience).
3. Consult official documentation and make as much examples on your own as possible.
4. Mock exams that I've took were of bad quality in comparison to well-known Java mocks from Enthuware. Unfortunately, it seems, that there's no reliable source of mock exams at the moment.
5. In comparison to OCA/OCP questions - actual Spring certification questions are more general, asking about concepts not about some tricky code execution or compilation errors.
6. Big note to everyone: don't waste your time learning Spring XML configuration. Certification exam doesn't simply ask about that.
P.S. If someone is interested about my own certification path - here's a github repository
where I've tried to answer all of the questions from Spring certification exam. The preparation took me about 5 months to be prepared.