I currently have KBB, the Princeton review for DAT, barron's, cliff's AP bio , gold standard and ACS for organic chem. I am good at trig and algebra, and pretty much all math, but not the cube thingin i havnt looked into those yet. I had average of the 96% gen chem and 98% on ochem when i took those classes. Im not sure about biology. I only familiar with genetics part. I am thinking purchasing the DAT destroyer and Math destroyer or ochem odyssey. But I dont know if they are necessary materials to review since i do have all the other books. I kind need some advice on if i should purchase it or not. thank you!