Several years ago, I read the original version, when it was titled _Food for the Spirit_. I recently picked up this, the current version. There is a new transcript of a radio interview with the auther. Not much else seems different. Possibly some small revisions were made elsewhere in the book, but it is not a substantal revision. I had hoped that the author would have revised more of the material.
Basically, I agree with the premise, that modern treatment of animals cannot be justified by any system of morality. Unfortunatly, some of the author's research was faulty. He relies too much on extra-biblical works of very questionable validity. For Christianity, the author spends an inordinate amount of time discussing "The Gospel of the Holy Twelve" which has about zero evidence for its being genuine. To someone who is not already convinced to be in favor of vegetarianism would suspect that if the author needs to spend so much time on disreputable sources then he can't have a very good case.
Likewise, for Buddhism, much of the pro-vegetarian sutra is not considered to be genuine.
A better tact for the author to have taken might have been to address more how modern inventions such as the factory farm are far different than historical animal husbandry. For Christians, I'd recommend _Is God a Vegetarian?_ The author of that book concludes that Jesus was NOT vegetarian, but Jesus didn't live today either.
For Jews, I'd recommend, _Judaism and Vegetarianism_. Both of these are available here at amazon.com.
Don't get me wrong, there is some good stuff here. But it seems that in an effort to prove his point, the author did not always use due-diligence to verify all the information, and as such weakens his case substantially.