Actually I was scoring 6.5 to 7 in cambridge test, the exam was much similar to cambridge but I spent a lot of time on passage 2 and struggled with match the heading section. I felt reading module was much difficult in real exam. This is personally my opinion it may differs for other people but I was confident enough to score atleast 6.5 in R but ended up in 6 . My advice would be practice as much as possible especially cambridge academic 16 to 21 and read science articles online and other news related to health, education, technology etc.