I bought this book mainly because I wanted to do some OpenSSL
programming, and from that point of view it wasn't very useful:
it's not designed as a programmer's guide at all, and there
are no example programs, etc..
However, once I got my programs done, this book was invaluable,
as what it does contain is full and clear descriptions of the
format of all SSL messages, and with this I was able to decode
the SSL messages that were being sent between client/server
and work out exactly what was going wrong with my programs.
I haven't come across this info anywhere else, and I think the
book is worth the money just for this material alone.