The Knight looks to be a good class. I'd be in favor of Warmage, Dread Necromancer, Beguiler and similar classes replacing both the Sorcerer and Specialist Wizards. The Duskblade looks broken to me, but I'm holding judgement because I like the idea behind the mechanics. The Dragon Shaman is pretty lame in both concept and mechanics, IMO.
The second chapter gets love/hate from me. I do kinda like the different archetypes, but I generally don't like the alternate class features (probably related to my loathing of substitution levels as a mechanic).
The feats are generally good. I love the fact that the fighter no longer taps out on their themes by 10th level. I also like tactical feats. I could live without the heritage feats, but they don't take much room.
Spells, I have no opinion on. I just haven't read them all and I'm pretty poor at guaging spell/caster power, anyway. I'm more a fan of the mundane classes.
Affiliations are a neat new mechanic, and one I plan on using. I'm indifferent to the swap-a-feat rules, but the rebuild quests are just silly. The "be a better player" section is something I'd love to make required reading, especially a couple of specific points.
Overall, it felt odd to type the above (it was all train of thought), because I openned up this thread feeling pretty similar to you. I (obviously) like the book, but I still don't see the "wow" factor.