Just wanted to endorse (is that the right word haha) Brightsky's Chinese Exam Revision Book. Personally I found the book to be a tremendous help, and played a big role in helping me receive my dream score. I come from a rural underrepresented school that has never had a chinese SL score above 40 before (highest previously was around 36), and this revision book gave me the help I needed to fully prepare myself and gave me a shot at competing against the very high number of chinese students who have spoke the language at home since birth.
The revision book general conversation part contained so many questions- each with 30-40 second answers filled with useful phrases and cheng yu's that would impress examiners and show you have an interest in the language and culture. I didn't use all of these questions (as he really covered just about every single question), and have no chance of memorising that amount of answers, but there was quite a few that I used in my own general conversation (and some phrases I used as well). I didn't particularly use the detailed study section as I did Pandas instead, but it was a good gauge at how many question I needed to answer.
IMO, the example essays were probably the most useful, although I really just made use of the many phrases and structures used (e.g 利弊兼具 or 权衡利弊 or 三思而行), that I'm guessing helped my essays stand out. They really help you to create a clear formulaic approach to these essays (more than just intro-body-concl), that make what you say really clear and structured (which according to my teacher is the most important part of the essay).
There is a very sophisticated use of vocabulary used however, which may seem daunting at first (idk if theres samples on here or not), but after learning these it really helps improve your chinese. Would recommend for anyone aiming high in the subject!
NB: this was meant to be a "brief testimonial" but hope it still conveys how much this book helped me