Generally speaking, this is a pretty good book which has concepts I agree with.
However, there are two things that I think are detrimental to the message :
1. The book argues that all sentient life matters equally, but at the same time it uses wording such as, "even animals matter." This is problematic because though it's saying all sentient life is equal, it's doing so using language that implies inferiority of other animals — especially when considering that humans are also animals, which is not acknowledged.
2. Using the idea of karma, the book essentially argues that if bad things happen to people, it's a result of their past actions, even in "a past life." This is something I fundamentally disagree with, as it is often totally unrelated when something bad happens to someone versus what they may have done in the past, and it totally shifts blame from the actions of those in control of the world to the misfortune beings on earth.
Otherwise, this has a lot of other great concepts to consider.