I have not taken the DAT yet but took the MCAT 2 years ago and performed really well (perfect 15 in some sections). I would say the reading is a lot easier on the DAT. A LOT. It is hard to compare the science sections because you read a short passage on the MCAT and answer questions about that whereas on the DAT it is all just a single question with an answer. The material is similar but the format is way different. (Yes, I know the MCAT has just Q and A's, too, but I think the majority of questions are from passages.) At this point I do not feel adequately prepared for the DAT, but if I had just taken my MCATs, I would feel good about it -- except I would brush up on my quantitative reasoning. That stuff I hadn't had since high school!