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.
Thats why I invested in video tapes as well.
DesiDentist