<p>Should I take a regular (~50 hrs) or a more rigorous (~100 hrs) course?</p>
<p>Depends on how much you want to improve, how much they are, which teacher you get, etc.</p>
<p>How many hours the course is is way, way less important than (1) the quality of the teacher (2) how much discipline you have to force yourself to practice (3) your current score and goal score and (4) whether the other students in the course have similar skills and goals. </p>
<p>Some kids might be better off with three one-hour private sessions than a 100-hour course. You need to match your goals to what the prep will offer.</p>