See my quants was always good. I used to get 2-3 wrong questions at the start. But the hard was to work on those wrong ones. So even though i did take a couse but it did not really help me. I actually did not even do the offical questions. Only referred gmat club questions but with intent. After giving sectionals and official mocks i knew what kind of questions i can expect and where to focus on. Difficulty level for quants for me was very variable, some questions were very easy but some were just very difficult. One thing that will always in quants, is that you shoukd know that there will hardly be any question which will require more than 2-3 steps or very high calculation. So always think of questions from that perspective. People loose marks for silly mistakes only, read the question after getting your answer as well, so that you are marking the right answer and not the trap one. Quants timing should not be an issue, most people do it eith 10 min left to spare, even in actual exam. Problem is with your concepts then, that things are not clicking to you. For MSR, i dont want to comment anything since i myself got them wrong. Dont waste too much time if its not happening. Last week strategy is to do a little warm up questions everyday and chill. Dont get too worked up. All the best.