Let me preface this by stating that of course this is an important book, and a translator's job is never easy.
That said, this book benefits from having the original Tibetan available, but suffers from a overly wordy phenomenologically influenced style of translation. Frankly, I have to read the Tibetan to understand what the translator is trying to convey in English
In general, a problem endemic with translations of Dzogchen texts is that the translators often unncessarily make what is relatively straight forward language in Tibetan a conceptual mess in English in their attempt to convey the meaning of Dzogchen into English.
I have generally NTS's work to be of highest literary caliber, when compared to that of Bruce Sterling, for example, or that of Gibson [whose writing matured with Idoru, IMO].
He scores very high in the inventiveness category and characterization as well.