I have all three. I started with Destroyer, and went over it a couple times at this point. In the beginning, I felt it was hard. Perhaps, I wasn't that prepared back then. I used Achiever for practice exams. I felt it is the hardest by far what I have used. Just last week, I did first exam on Top Score, I felt it was easier than Achiever. Again, it could just because I am more prepared this time. I have my DAT coming up in less than 2 weeks. I am going to go over what I have multiple times to improve my scores, plus 2 more top score exams. Hope this will work. Any suggestions for me? Thanks