Very good options for Edges and Hindrances as well.
Some nice new equipment options.
Doesn't quite live up to the promise of the Interface Zero book.
Zeeks feel more "essential" to me than some of the alternate races in the main IZ book, to the point that I think I would have largely preferred this material (the mechanics, especially) being in there instead.
The Occupations section opens up some new options that make the occupations from the main book feel a bit lacking in comparison.