I have just finished reading the book "In search of the truth" written by Nicholas Mavromagoulos. In the book Nicholas and his friend George tell about their years as members of The Watchtower Society, and their journey to the orthodox church.
The books can be written both in greek and in english here:http://www.oodegr.com/english/biblia/biog1/perieh.htm
I found the book very exciting and informative and it explained very well the situation of those who are a part of this organizationnd their struggle in matters of dogma and faith.
Anotther thing that I found especially unique about the book was that it more than any other book I have read by ex-witnesses clearly descripe the dogmatic differencies between the Watchtower Society and the Orthodox Church. The narrator takes good time in details to explain the heresies of the Society and how the orthodox church view each topic.
The book have appearently also recieved praise from many orthodox hierarchs including Patriarch Peter of Alexandria and all of Africa(of blessed memory) and several athonite monastics(most of the reviews was in greek so I was unable to read all of them).
For those who would like to boy the book it can be bought on the website of the monastery of st Johnhttp://www.stjohnsbookstore.com/node/1565
It is a very exciting book to read and I would definitely recommend it.