I decided to pick this one up after looking at it and while I think the classes have some definite potiential, but once again, it's the editing and design of the book are where I have problems.
Problem One: The Flip Book Factor: Here I am trying to create a Swordsage, but I am constantly having to flip back and forth from this page to that one. The Swordsage table is on page 16, but to find out what level maneuvers you can use, you have to go to page 39. One of the Swordsage's abilities, Discipline Focus, is based off weapons favored by a chosen discipline, see chapter 4. But oops, the Art department did not include numbers on the chapter pages, so it is back to the index to find where chapter 4 starts, but don't bother. Why? Because the information you need is not in chapter 4, it is in Chapter 2 under Blade Meditation feat (pg 28) and in Chapter 3 under Maneuvers and Stances (pg 41).
Confused yet?
Problem Two: Complex NPCs: Let's say you need a 5th level Wizard. No problem! 4 zero level, 3 first level, 2 second level and 1 third level spells and while most of us can choose them from memory, you can use the spell list as well.
Now let's say you need a 5th level Swordsage. OK, you get 10 maneuvers, but without that vancian chart most spellcasters have, you are going to have to go back and figure out at what class level he had access to what maneuver level. So that means 7 first level, 2 second level and 1 third level, plus take into account that you can take lower level maneuvers and you can upgrade one at 4th. Now you can pick them, but remember that some maneuvers have prerequisites of other maneuvers from the same discipline and the same applies to most of the Swordsage feats.
And that is just a 5th level Swordsage, imagine a 10th level one. NPC design should not be this complex. If they are planing a web enhancement for this book, some prestated NPCs would be a good choice.
Problem Three: The Closed Book: It is called the Book of Nine Sword because there are nine disciplines, but what if I want more? We have a fire based discipline in the Desert Wind, but what about an Electrical or Cold based one? We have a Stealthy Ninja discipline in the Shadow Hand, but what about a Pirate/ Corsair, water based discipline?
Part of the fun of D&D is that you can shape and add to your world by creating new spells and monsters. But many of these recent books are trying to be everything in one book. I have yet to find anything on adapting or changing the disciplines nor is there rules on adding new maneuvers and stances to the disciplines.
If I was to use this book in D20 Rokugan for example, I would change Desert Wind into Fury of Osano-Wo by changing fire to lightning. The weapon groupings are a bit weird too, Diamond Mind has Rapier, Short Spear, Trident and Katana. That's several different cultures combined, what if I want to keep it in one culture? I was also surprised that this book did not include a section of how to use it in Eberron or Forgotten Realms as most books do.
So far both Tomes (Magic & Battle) do present some new and intriguing concepts, but they need to do a better job in how they present them.
Either that or put the "Advanced" back in front of the D&D.