C1 Advanced preparation
With a big thanks to Ronald Zwiers for the efficient approach, he gave clear information and motivation even when I was considering abandoning the C1 Proficiency exam. As a result, by now I even have the C2 Proficiency certificate under my belt!
Highly professional organization, communicating smoothly and helpful with practical questions. I also found the self-study pack useful and user-friendly as a refresher and to become familiar with the format of the exam.