Agreed, destroyer is the most valuable resource for each science. It may be a slight bit more difficult than the DAT, but is a preparation tool, not a practice test. You want to prepare for something a little morer difficult so that when something wierd comes up you have no problems answering it. Know the destroyer cold, cover to cover, and understand each and every solution. It is the only way to do well. I got 2 questions wrong in Gen Chem and orgo, and there were two mistakes on my DAT both in orgo. It is very feasible to get a 30 on those 2 sections just from completely understanding destroyer. I can not recommend it more.