I listened to the audio version of this book and found it absolutely outstanding - I am going to buy the book to have on my shelf. While the target audience, I believe, was prospective missionaries and I believe many apply it to lay and pastoral leadership in the church, I found the tenets of this book also very applicable as my role as father and husband and spiritual leader of my household. Also, as a Naval officer, it is one of the best books on ANY kind of leadership I have read. The principles are foundational and will be successful in any aspect of your life.
I have read through many leadership books and this is one of the greatest books I have ever worked through related to leadership. Out of all the books I had to buy and read during my seminary experience (more than I wish to try to count) this is in my top two!