It's all a matter of opinion and how well you feel about the material yourself. I have to 2008 version, but a friend of mine has the 2010 version. There definitely are new questions and materials, which in my mind I think is worth it alone. The Destroyer definitely helped me a lot between my first and second time taking the DAT. However, you have to keep in mind, that you have to use other sources as well, it's all just what you think.
If you think the new version is going to give you more of an edge I would take it! I have been on the boards since I started the whole studying process and I've seen then trends in scores go through the roof this cycle! The Destroyer gotta be doing something right if so many people keep recommending it.