In my some 43 years of reading in the field of studies about the Baha'i Writings, this is my all-time favorite book! Highest possible recommendation. Even the learned introduction by Dr. Todd Lawson alone is a gold mine worth the modest cost of the book.
I have reviewed the book -- and shared the story of its author -who passed away well over 20 years ago -- elsewhere online: http://bahaimosaic.blogspot.com/2012/07/learn-well-this-tablet.html