before reviewing the roadmaps i had taken a lot of notes from chad's videos and i had gone through them quite a bit..
given that, it took me about an hour or so to go through the roadmaps. there were only a few reactions that i was unfamiliar with, because they were not covered by chad. the rest of them i knew right off the bat because i understood basic mechanisms. trust me it saves a WHOLE lot of time and it makes life easier by learning the mechanisms. this way my OC score improved 6 points. hope this helps you.