My GPA is 3.79. I have a Bachelors in Biology and was on the alternate list for my in-state school for last cycle. My in-state is my first choice, so hopefully my significant bump up on my DAT will put me in this years class.
I took a 5 week Kaplan DAT prep course. It was definitely helpful in the sciences and QR sections. The strategies for PAT were great, but the practice problems they provide you with are not as difficult as the actual DAT. I could have scored better if I had practiced harder problems. I also felt like I could have scored 2-3 points higher on both QR and RC if I had just spent more time studying for them. The bulk of my study time went towards natural sciences and PAT.
The actual in-class portion of the Kaplan course was pointless really, but the study materials they provide you with are very good (hundreds of flash cards, section tests, practice problems, full length DAT practice, score analysis). One of the key things that allowed me to succeed was taking full-length DAT practice tests. If you do this you will know exactly what to expect on test day, and will be well-conditioned to take the test. That is something that many overlook. The DAT can be rigorous at 4.5 hours. I was much less mentally drained after and during taking the DAT the second time because I was conditioned for it.