Best Fate book to date hands down! Well Written, Organized and Explained. Takes the best features from every other book I have read and then gives it a twits to improve it. And if that wasn't enough it still contains the options of previous books just in case you prefer it that way.
Though Fate is story oriented and balance usually isn't an issue. This gives you all the tools to make your fate game more balanced through its awesome point buy approach. This is truly the next evolution of fate.
If you want to play Dresden, StarBlazer, Diaspora, Shadow of the Century or Legends of Angelerre, buying those books might be good, especially for all the source content, but even if you do, this book is a MUST. The ideas and option will improve any of those games.
HOWEVER if you are looking to convert a campaign, try a new system, make your own home brew campaign or simply have the best FATE book out there, there is nothing more to think a bout. This is it.