I have the GS book and DVD's. I wouldn't suggest getting the DVD's to study from. What I do is study from the book, as well as EK, there are others review books out there.....When I am tired of studying or need a break or only have a half hour or so I will watch some of the DVD's. They are kind of boreing but it covers important information. I haven't taken the MCAT yet but the DVD's did help me get an A in my organic chem class so the material is there.
So point is get them if you have the money to HELP you study but by NO means should they be your only source of studying, its just not enough. Hope this helps.