Honestly, The Final Fury was not a bad story. In fact, I actually enjoyed it. After an extremely well written and action packed first INVASION! Novel - First Strike, featuring Captain Kirk and crew - the following stories featuring the TNG (Soldiers of Fear) and DS9 (Times Enemy) crews were a terrible let down. This book, however, capped off the ending nicely.
It was nice to se that the author actually put some thinking and creativity into the story (unlike Soldiers of Fear). However, this goes without saying that there were some storyline aspects that bordered on outrageous. Primarily, Chakotay taking Voyager into a star. Plot-wise, at times this book did get somewhat technical in the end, and it was difficult to follow. (Not overly difficult, however, it's just that some times my mind wanders during these slower parts.)
The characters in The Final Fury were fairly well developed (unlike Soldiers of Fear) and they were not emotionless clones of the TV characters that we all know and love (unlike Soldiers of Fear). Even an underdeveloped character like Lieutenant Redbay - of Soldiers of Fear fame - was brought back into this book (sorry for the minor spoiler) and was made into a well-written character.
To sum up, read Invasion First Strike, find out what happens in the next two novels, and then skip to this book, The Final Fury.
(By the way, did I tell you I didn't like The TNG Invasion book - Soldiers of Fear?)