Hey for Undergraduate Medicine, Casper is only needed for Curtin as of right now. It is also used for Postgraduate Medicine at Wollongong and Notre Dame. I completed the Casper for Postgraduate Medicine at Notre Dame last month and got my results back yesterday. I received the 4th quartile (top quartile 75th - 100th percentile) and did barely any practice. Most of the content is self-explanatory and as long as you have a balanced viewpoint and are empathetic, you should do fine. In saying that, once you register, there are a few practice tests on the Casper website which is quite representative of the real exam, and highly recommend increasing your typing speed as the Writing Section is very time pressured so having a high typing speed will help you out.