The main character is a bit of a Mary Sue -- she is remarkably capable in so many areas, and nearly everybody likes her, admires her, wants to be like her when they grow up. But, of course, Eli doesn't realize just how impressive and attractive she is.
On the plus side, the plot moves quickly, the scientific and technical ideas are plausible, and the main character *is* likable, even if subtle character development is not present. In short, if you liked the beginning of the series, you'll probably like all of the Eli Donsaii books.
Vaz is a quick, entertaining read. I noticed a couple of places where names were transposed, but in general it's clean and well edited. Unlike in the the Ell stories by the same author, the protagonist is an adult when the challenges of this book start. However, Vaz is a borderline autist, so despite having a family and a respected job position he has little clue on other people's reactions. On the other hand, others don't understand Vaz's talents nearly as well as they think.
Vaz is almost ridiculously capable, intellectually and, it turns out, physically. What makes him interesting and engaging is his lack of social skills, and almost childlike but logical reasoning about other people's reactions when he is forced to deal with them.
The author has succeeded in creating an interesting, endearing character in Vaz. The secondary characters are lightly sketched, and the villains are mostly flat, but the action makes a good showpiece for the Vaz's exposure of his capabilities. It also allows Vaz to demonstrate his fierce love for his family--and eventually to show how it's reciprocated.