1. Its author merges harmonically multiple sources. Among them are Buddhist authors, not just Indian, but also Tibetan, Chinese and Japanese, but also their contemporary interpreters (from Doniger to Zimmerman), as well as Sanskrit writers (from Candragomin to Subandhu), European writers (from Musil to Sartre!), European philosophers (from Descartes to Marx and Sextus Empiricus), scientists (predominantly Darwin and other scholars of biology and evolution) and contemporary Analytic philosophers (from Dummett to Kripke).
2. Kachru takes seriously Vasubandhu’s arguments, e.g., on causality and on perception, both of which cannot be just read as based on the interaction of two solid and mind-independent entities (epistemology might here have to do more with philosophy of action than with ontology, and not just because of the theory of karman).
3. Kachru also takes seriously Vasubandhu’s “conceptual toolkit”, trying to understand what it means to think for a Buddhist thinker of his time and place. Note that this creates a tension with No. 2, but this is a productive tension.
4. Kachru is a self-reflective authors, openly discussing his methodology, which he does not take for granted as the only possible one (or “the right one”).
5. Kachru also shares interesting thoughts about his translation of the Viṃśikā, which he, meritoriously, adds to the book.

What does No. 3 mean for the analysis of the Viṃśikā? Primarily, that SK invites us to take seriously Vasubandhu’s use of his examples (primarily: dreams, pretas and life in hell). SK stresses that dreams should not be understood as the example in a Sanskrit syllogism (as they have been later used, for instance in Advaita Vedānta). Similarly, he dwells with what it means to discuss pretas and beings in hell as alternative viewpoints that relativize the privileged position of our POV on reality.

The result is that one finishes the book feeling less sure about the “solidity” of the external world. The past feels less safely past and the present’s dependence to it opens up to the possibility of a continuity between the two and, hence, of processes rather than concluded events in which entities persisting through time interact with each other. What is the alternative? One possibility, enactivism, is discussed in chapter 5 using the work of Matthew MacKenzie and Evan Thompson. SK appears to be positively impressed by their work, but sees “reasons to be cautious”. Why?
First of all,

“As MacKenzie notes, as a theoretical program, enactivism involves several claims. One of its claims plainly does not apply: perceptual experience is not itself considered a form of action (or even activity) by Vasubandhu (nor indeed, by any Buddhist philosopher in his orbit, as far as I know)” (p. 123).

Moreover,

As I read him, Vasubandhu’s way of entangling features of the environ- ment and living beings does not depend on facts in the present, nor is it derived from scrutiny of the dynamic inner workings of an organism with an eye on the way in which an organism structures its environment and itself over time. […] Vasubandhu […] does not have the resources to make the kinds of claims MacKenzie thinks Buddhists should be making” (p. 124).

You can also read an endless thread by me on this book on Twitter, here.