Both fascinating and seriously analytic.
Interweaving most of 20th century most important sociological theories (social theory, gender theory, ...) with a serious analysis of Star Trek episodes, the authors manage to give an interesting and thought-provoking read about not only Star Trek but also larger trends.
One of the most successful aspects is the ongoing theme of how different "TOS" (aka "The Old Star Trek") is from all the later Star Treks, and how they all show the widely different views on race/racism, ethnocentrism, morality, gender etc. between the time the show was first conceived and the later series. Everything is very successfully linked to and analyzed through the lens of evolving social theories (with a satisfying meta-analysis that also looks at different schools of sociology and their relationship with Star Trek).
Interestingly, the book is also very zeitgeisty: Written in the late 90s, it almost completely avoids any analysis (and criticism) of Star Trek's interesting but very difficult relation to homosexuality and lgbt concerns. Certainly had it been written today, probably a whole chapter would have been devoted to it.
Anyway, a must-read if you're the kind of Star Trek fan who doesn't judge episodes merely on how entertaining they are.