I don't see comprehension as an issue. I have never been a particularly fast reader, but as I have gotten older I read much more slowly. My retention is also not great. When I was studying for the bar exam I took a prep course which entailed simply writing down what the lecturer spoke for 8 hours a day. This went on for 3 months. It was boring as hell, but effective. I had gone to law school in a different state than where I was seeking admission, so I had to cram a lot into my head, while absorbing the material enough to be able to discuss it while writing the exam. It worked. I passed, but I honestly felt like I forgot everything three days after the test. If I tried to read that stuff on my own I am sure I would not have absorbed it as well.