The "Coyote" series, of which this is the eighth installment, has always been at its best when the characters engage in human conflicts while exploring the exotic colony world, Coyote. The weakest points have always been Steele's aliens (who are essentially humans in fancy dress), and Steele's physics (which is bad).
The advent of Hex is a worry, then, because it features a huge circumstellar space habitat (the "Hex" of the title) populated by many different races of aliens. There's every indication, by the end of the book, that Steele is setting up for sequels in which his human characters roam around Hex and encounter new aliens. But the aliens we encounter in this novel are just Steele's usual slightly foreign people, and the physics of the Dyson-sphere habitat is catastrophically bad. He doesn't get centrifugal pseudogravity right; he doesn't get simple orbital mechanics right; he messes up simple mathematics (calculates an area, calls it a volume, then gives it in erroneous scientific notation with unit of length). This is really not a place Steele should be, and I wish he'd head back to some more human dramas on Coyote.
If bad physics doesn't bother you, and you don't mind aliens from Star Trek central casting, you'll find a mildly engaging adventure in which humans get into trouble, get out of trouble and get into more trouble, in strange locations. There's a central character arc in which an estranged mother and son come together through adversity, but it's rather sketchily and unconvincingly drawn, with a saccharine conclusion worthy of Steven Spielberg.
Oh - and the octagonal diagram of a hexagon that some reviewers at Amazon.com have complained about? That's been fixed in my mass-market Ace paperback.