Whats the name of the book? Would be very interested in picking up a copy.
The Romero Jacare Book I have is called -
Brazilian Jiu-Jitsu Fighting Strategies (Paperback)
by Romero "Jacare" Cavalcanti (Author), Mark Van Schuyver (Author).
I'm pretty sure that it will complement the instructional videos, personally I think the most important parts of this book are all the fighting strategies.
However, keep in mind that I am a beggining to mid level BJJ guy - so you may find it redundant if you are a mid to high level!