The tapes were by no means comprehensive of the material you should know. The biology section was OK. I didn't find the chemistry very useful. I think chemistry is not something you can learn from an audio tape. If you have a hundred bucks to blow I guess it's worth buying especially if you're spending a couple hours a day commuting. I used the Kaplan book and the audio tapes although I didn't score very well. Wish I would have spent more time taking practice tests. I felt like I knew the material pretty well but I totally choked on the exam. Hope to retake it in a month.
I have the DAT tapes and they are okay. They really help you skim the topics. If you have done a good job studying (detailed) then these tapes will really help you remember stuff you learned. I think I'm going to listen to them a couple days before my dat or maybe the day of just to remember stuff.
There are only three tapes. Not worth a 100 bucks, but remember when you see, hear, and learn then you will not forget the information.