Since I came back from Strasbourg I didn't really have time to resume the seminar about paper C I could follow last week.
It was rather intense, and also very useful, as for papers A and B. But I could notice a difference: for the paper C seminar I strongly suggest to read the parts of the paper C book to be read before coming to the seminar. I did it and it helped me understand and easily follow the first afternoon of this seminar. On the contrary, I saw some colleagues who hadn't read the parts of the book and they seemed rather lost at the beginning.
After that, the seminar comprises a big practical part with a training based on a former paper C, and then a mock examination in real exam condition, except that the mock trial was split in two parts.
After having followed the seminars, I feel more confident than I would probably have felt if I had continued to prepare myself alone.