Being an ex-pre med, I took this class. It'd be a BIG waste for the DAT since the questions are completely different. They teach you to the MCAT's style, which involves passages of information and questions related to these passages. They teach you to extrapolate information and apply outside info to get the answeres.
Now, if you've taken a DAT practice test, you'll know the questions are straight-forward, either you know it or you don't. So their teaching style wouldn't benefit you. But if you need to review basic concepts, the Hyperlearning books are fantastic. They're basically condensed textbooks with some really nice explanations for Bio, Gchem, Ochem, and Physics (MCAT has physics, DAT doesn't). Only problem is, these won't have DAT practice problems (obviously).
I'd say buy the books if you need to brush up on the concepts, but overall the class would be a big waste. The lecture stuff is basically right outta the book, and you'd also receive a bunch of practice works books and practice tests that you couldn't use since they're for the MCAT.