It read like glorified fan fiction, and lacked nearly all of the interest the previous seven books contained.
Hermione was stilted and awkward. She lacked her usual cleverness and virtually all of her charm. I do like the idea of her being Minister. It suites her.
Much of Draco's dialogue and many of his interactions with other characters seemed out of place, and rather unexpected. However, if you believe that Draco deserved a redemption, this book will satisfy your craving.
Ron confused me as well. He has, for some reason, adopted the personalities of Fred and George and has gone into the family business of making joke products. It seemed like lazy writing; Ron spent his whole life trying to make a name for himself. He never wanted to be in the shadow of his older siblings, which seems to have been forgotten by the writers.
The new characters are charming enough, but the conflict feels forced. From what we know about Harry, he doesn't seem like the type to force his son apart from a close friend of his (consider, in particular, Albus's other namesake, Severus.) Harry witnessed, through Snape's memories, how his friendship with Lily fell apart. You would think that Harry would know better than to tear apart true friends, because he's seen the effects that can have on a person.
Harry just seemed irrational. He spent his whole childhood being doubted and being estranged from his family and, at times, the wizarding community, and somehow we're supposed to believe he doesn't love and treasure his son? There's no logic to that. I'm entirely confident that he would work harder to understand his son, rather than react the way he did.
And I guess here's my final complaint, for this post at least:
Amos makes the point that many people have "died for the Boy Who Lived." But I call bullshit. How many deaths is Harry actually directly responsible for? James, Lily, Dumbledore, and Snape. I don't think that Harry is directly responsible for the deaths at the Battle of Hogwarts. Those wizards and witches died in an effort to stop a great evil that was plaguing the wizarding world. It was about more than just Harry.
That's all for know. There is a lot more to complain about, when I think about it. It's a pretty shit story.