There is indeed some good information on the sites, although I cannot totally buy into their bias against consuming any meat, animal fats or cholesterol.
Personally I think that a mostly vegetarian mostly raw diet is the healthiest, and is an essential tool to use in fighting cancer and other serious conditions. On the other hand, I have found nothing that convinces me that an only vegetarian diet is the healthiest for most people and I note that the longest lived and healthiest groups of peoples in the world ALL consume at least some meat and/or fish in their diets.
I also believe the while T. Colin Campbell's book itself (The China Study) has quite a bit of good information, it is also flawed in many respects and Campbell jumps to conclusions to support his personal bias that are not supported by actual facts or even his own observations.
Not to mention that his conclusions fly in the face of millions of years of prior life on this planet (whether you call it evolution or adaption or whatever).