I went to these for my HSC. They weren't absolutely amazing, but I still thought they were pretty good. I enjoyed English (depends on the lecturer though) but I wouldn't recommend the creative writing one (waste of time imo). Maths provided good overall revision for all the topics, particularly some of the smaller subtopics I would've otherwise forgotten about @__@ or placed less emphasis on in studying for, as well as some neat trick questions. Very rushed towards the end of every lecture though, never finished any of the booklets (although they did provide answers if you were bothered to go through yourself). It was a lot more helpful than what I would've been studying at home by myself though - you get a range of perspectives from the lecturers, and generally they're HSC markers so they tell you what (in their experience) the marking centre looks for.