This novelization is satisfactory as a novelization of a film. For someone wanting to relive the film experience, but who for some reason is unable to watch the film, this book offers a good solution. If you have not seen the film, watch that first before deciding if you want to read this book (and if you really want to read my review, do so after having seen the film). I will not recap the plot here, since it is essentially and of necessity the plot of the movie.
There is some additional context provided by deleted scenes, but the nature of a novelization based on an earlier screenplay or cut of a film is that it sometimes contradicts the final film. Thus, some of the extra context is diminished by the fact that it does not actually contextualize the events of the film. For instance, the Starkiller Base weapon is given a lot more technical detail–it can punch through hyperspace so that it is deployed instantly, and it is powered by dark matter. However, in the film it appears that it is powered by the energy of its nearby sun, and it fires a beam of energy that is visible basically everywhere in the galaxy at once and follows a linear path through space, splitting apart to hit multiple targets at the end point. The difference is not huge, and I won’t claim that it ruins my reading experience, but it does mean that any additional insight gained by reading this book really only applies to the narrative of the book itself and not necessarily to the movie.
The movie informs the book, but the book does not inform the movie. It thus feels detached and very much like the promotional merchandising that it is.
Despite that, I can’t really criticize the quality of the writing itself, for what it’s worth.