I'm not totally sure how much it factors in to the overall score. On your score report, you will see a score for each section but then as I understand it what is reported to schools (and listed for you to see) is only your Total Science/Academic Average. Reading comprehension only factors into the academic average score and not total science (and likewise for quantitative reasoning). I personally didn't think reading comprehension was that hard. Kaplan's strategy for taking notes on each paragraph on your sheet as you go helped me get through the section quickly!
