Maybe I'm just into fighters more, but so far I don't like it as much as Complete Warrior. What I've checked out so far is really well done though, none of the prestige classes are boring and they got some pretty balanced versions of the spontaneous metamagic feats. The 3 new base classes are interesting, the Warlock uses incantations instead of spells. Blood Magus prestige class was upped in power to match the stiff prerequisites (namely you have to die and be brought back, which would usually mean you'd need to lose a level to enter it). There is a summon familar feat that lets you get a familar and count all arcane caster levels as sor/wiz levels for its strength. Another prestige class lets bards advance bardic music and eventually gain 9th level sorcerer spells.
One new prestige class that caught my eye was the Green Star Adept. Once each generation, the comet Alhazarde- the legendary green star- visits the night skies, and strange stuff happens. This lasts for about a week, and parts of the comet fall off and their starmetal can be collected and brewed into a potion. It costs 1000 gp to prepare, and the Green Star Adept must consume one once per level, making it a quite costly prestige class. You gain none of the class benefits when you level until you have consumed another elixer. Eventually the class turns you into a green statue of yourself and you become the construct type.