I finally started passing exams once I stopped trying to do practice SIMS and focused more effort into MCQs and really understanding the concepts. If you know the concepts and read carefully, you'll know how to answer the SIMS. However, I do think practicing how to research the Authoritative Literature is helpful.
FAR- 67, 69, 57, 77
AUD- 71, 81
REG- 73, 84
BEC- 87