This is the fourth and final book in Flynn's Firestar series, a series that started out with a bang but ended closer to a whimper. If a near-present-day hard SF series about how we should be exploring space appeals, you definitely should read Firestar if you haven't. If it leaves you wanting more, keep reading the series, but be warned that the later books have less punch. If you haven't read the series, don't read it out of order; almost all of the characters are ongoing and you won't really understand the characters in Falling Stars if you don't know where they came from.
The best thing about this book is that Jimmy Poole, who started out as a friendless fat geek in high school and went on to become the leading hacker of the age and a real son of a bitch, actually develops some human decency. This was comforting because I see a lot of myself in Jimmy Poole. The worst thing about this book is that the big loose end from Lodestar, the third book, isn't satisfyingly put to bed. The characters have come up with their own explanation of the puzzle which justifies the way they handle it as the right solution, but we don't get the confirmation that it really *was* the right answer, so we're left wanting to know how things turn out in the world. However, the state that the characters are left in seems to confirm that this really is the last book in the series: the ongoing characters have, between them, have had quite a bit of control of worldwide events in the series, but by the end of this book, the world has moved on and to continue the big story would require Flynn to come up with a whole lot of new characters and background.
On its own merits, this isn't a bad book -- it certainly kept me turning pages -- but I really only recommend it as the not-quite-completely-satisfying conclusion to the series. 7 out of 10.