I didn't do well on any practice RC exam on CDP, kaplan bb and kaplan course, and another (forgot which). I crushed it for the real DAT and thought it was easier than the practice RC. To me, it seems like the only things you can do to prepare for it are taking practice exams to get used to the format, types of questions, work out your strategy, and to read a lot of short-medium sized articles. I read a lot of journal articles and magazine articles on my phone to speed up my reading. I'm sure other people have good ways to prepare. Plus, maybe all you need to do is figure out a good strategy that works for you. There are a lot.
