This is quite a good book for those wanting an extra focus on their martial characters. It has plenty of Good, Bad and OK parts.
First the Good, it is laid out pretty well although the Fantasy Warfare section could probably be split into some smaller chapters but that's just a minor problem. The introduction is clear but isn't anything special.
The standard classes are actually pretty good. the Hexblade stands out by far. A great addition to the classes, it represents a character who blurs the line between a sorceror and a fighter. Starting with the fighter's BAB progression and HD he gains several hexes until finally at 4th level he gains spells which mostly strengthen his fighting ability. One of my PCs is a multiclass Druid/Hexblade hoping to become an Arcane Hierophant (Races of the Wild). The samurai and the swashbuckler are quite good but not perfect, in my opinion, it is much better to progress as a fighter than a samurai. The swashbuckler is a bit better and it is understandable why it was added but apart from a its special abilities it is a less armoured fighter. The prestige classes are extremely good and open up a lot of great possibilities (such as a Drunken Master/Tattooed Monk combo). Other notables are the cavalier, spellsinger, knight of the chalice, kensai, halfling outrider, hunter of the dead and bear warrior as well as many others found in the book. The feats are pretty good especially ones like the Flying Kick, Improved Toughness and some of the Barbarian-themed feats.
Next, the Bad. The thing that jumps to mind is the art. Although not all bad, the quality of the art came as a big surprise to me. They are most prominent in the prestige classes section. I just did not like the art for the Halfling Outrider, Dervish, Dark Hunter, Mindspy, Occult Slayer, Nature's Warrior, Master of the Unseen hand, Hulking Hurler and Warshaper. However, there are some diamonds in the rough such as the Thayan Knight, Hunter of the Dead, Order of the Bow, Eye of Gruumsh, Cavalier and Frenzied Berserker. In my opinion, the rest are ok.
Finally, the OK. The Fantasy Warfare's content is a mixture of good and bad. The start where it suggests either Historical Warfare or Modern-Inspired Warfare when introducing war into the game. This put me off it a bit as I would like to have used both if it hadn't set them poles apart without even mentioning a medium. The mercenary campaign section is pretty good although if you want to put war into your game I would suggest Heroes of Battle instead. The Sporting Combat, Magic Items, Epic Warrior and the Weapon sections are all pretty good but the Warrior Campaign section and variant rangers and paladins (found at the start of the book),although interesting, seem redundant since they describe a setting where magic doesn't exist. It seems, to me, that it takes away the variety of the game if every player is a variant of a martial character.
To conclude, I think that this is a great book to use in conjunction with other Dungeons and Dragons 3rd and 3.5 edition supplements and introduces a lot of interesting ideas to be incorporated into the game by both players and DMs. All in all, I would give this book a 4/5 rating.