Fast, straightforward and shooty, this is great golden era inspired sci-fi. The gates are alien and weird; the nano-technology is filled with hand waving, but feels limited (particularly by requiring time), while the other technologies feel like reasonable extrapolations–and are completely taken for granted by the locals. The hero is a craft, clandestine survivor–he reminded me a bit of the Stainless Steel Rat.
It’s a fun universe with a lot of “now” aspects carrying forward–Corporations are much like today’s multinationals, just expanded to mutli-planetary. Similarly, despite extensive body modding, gender is basically 20th century, while race has mostly dropped out of description and consideration.
Again, it’s fun and fast–I’ll read the sequels from the library and enthusiastically recommended it to Jennifer.