If you ever wanted to know anything about the Borg this is the book for you. It has details about their culture, vessels, lifestyles (If they can be called that) and all the information you need to run them as an adversary or play one as a character.
This sourcebook also gives a good amount of detail concerning the varied races and worlds of the Delta Quadrant first as an in character explanation from Starfleet and then in the second half of the book with all the rules needed for your game.
If there was one complaint I had it would be that the Delta Quadrant Starships section didn't have images of all the starships. Certainly they're readily available online but it would have been nice to see them in the book especially given the high quality of the art used.
All in all, this is a great Sourcebook for any Star Trek fan and an indispensible reference for any Borgiphile out there.
[5 of 5 Stars!]