"Hilldiggers" is very much unlike other Asher's books. It is as if it's written by a different person. It's boring.
I love his "Skinner" and still re-read it every now and then; the "Voyage..." is almost just as good. His Cormac books are also finely written. This one, I could barely finish it. The plot is predictable, all characters are flat and the writing style is extremely boring: page after page of monotonous narrative, irrelevant details and dry dialogs. No sense of humor whatsoever, and in fact very little emotions at all.
Despite his obsession with details, Asher doesn't bother to be consistent with his prior Spatterjay books (one example: in both the "Skinner" and the "Voyage..." hoopers occasionally get dunked into the deadly Spatterjay sea and, while being eaten alive by various creatures, they do keep afloat like any normal human would. In "Hilldiggers", the Hooper character McCrooger is for some reason much denser than normal people and would instantly sink to the bottom). Not to mention the idea of sending the Hooper, twice-infected by conflicting viruses, to make first contact with a paranoid and warlike civilization... Not to mention the silly "tiger-on-the-ball" Tigger drone... Or the four obviously suspicious "worm children" so easily allowed to raise to the top of the society...
If you like Asher and don't want to be disappointed, stick to his earlier Spatterjay books and avoid this one.