I was wondering if I should buy the Kaplan review notes since it seems like almost everyone uses it to study for the OAT. I got the blue book (http://www.amazon.com/Kaplan-OAT/dp/1609781090) from my local library, but I don't know if it will be enough. Should I also buy the review notes as well? Can someone tell me what the difference is or if i will just be paying for the same book with a different cover?