From what I have read so far, Steinitz's text is well written.  He shows, albeit indirectly, how Ligeti's early-life experiences helped to shape his music.  Reading this book has been an eye-opening experience for me.  I have learned a lot of interesting and valuable information about Ligeti and his music.
After I have finished reading this book, I will post a full review.  Right now I will say that this book is worth reading.