OK; more comment than review (too busy to get through the whole book yet...)
Disclaimers: I am not a student of FCS, but I do train in Sayoc Kali where Tuhon Ray is my senior. In addition, I have trained in several of the other systems comprising FCS...so I may be biased.
I have had several opportunities to train w/ Tuhon Ray (hereafter TR, not to be confused with Teddy Roosevelt). After about 54 seconds on the mat you realize 1) this guy is smooth and fluid 2) lot of skill there 3) if he doesn't have a slower speed I will have a devil of a time getting this material.
Later you realize just how many different places TR is drawing from; for me he makes a very logical bridge from Modern Arnis into Sayoc Kali; both flavors are there if you make the connections. The real strength of the new book is a detailed conceptual discussion of where the different theories and arts fit together to make a coherent whole. The reader gets a tremendous overview of how one synthesizes a lot of material into a viable final product.
There is some technique presentation as well, mostly as examples. The problem, and we all know this, is that sophisticated technique can not be taught in a book. What I did find very helpful was the discovery that some of the exemplar techniques were the same as moves TR taught in last weekend's DC area seminar....a great bonus that is helping with retention and absorbtion.
The short conclusion- there are relatively few books on FMA anyway, and if, as a serious practitioner, you buy more than the one or two by your own instructor you probably buy them all anyway (yes, I'm guilty). The difference here is you won't go " mmm, another nice history book" when you get it. TR has written a good solid overview of the FCS system which is essential, I think, for those in that system (or who otherwise study with TR, even at intermittent seminars). For other FMA players...still well worth having; you will learn some things and enjoy the final product.