I have the book and find it very impressive.
Some of the more scientifically exacting minds would say that such a broad population study contains too many variables that aren't being controlled for, so we can't be sure it's the food, or possibly some other environmental factors, that's causing all the cancers, etc. Such people as local Registered Dietician Mark Rifkin, would prefer to see a more rigorous double blind study or studies.
Other doubters would ask why the scientific community hasn't more fully embraced the findings of the China Study. But I agree that the study was most impressive, and that until scientists are personally ready to make some big dietary changes, the same resistance will appear in their professional stance as well.