Well, at first yah. I complete the book tomorrow. The best I've done in orgo is 4 wrong, worst is 22. Bio is about 12-18 (hasn't really changed much for me). Gen chem went from about missing 22/30 to missing 11/30. You just have to go through it. You should be fine if you finish the book and memorize roadmaps.
To be frank, I think bio is the hardest section since it's the biggest.