Given that it's the only book that offers an approach to the art and architecture of the Kathmandu Valley, it deserves praise.
However, it's only of interest to art historians or history enthusiasts (not to tourists). And, unfortunately, it's very formalistic, very historicist, and outdated in its understanding of aesthetics. This makes it, despite its undeniable value, a somewhat dry, abstract, and....yes, a tedious read.
Anyway, unvaluable when it provides guide-maps to temples and iconographic diagrams.