There's this thing that happens when authors become famous -- suddenly, they have enough power to not get edited. And the thing is, people need editors, or beta readers, or someone to tell them, "Hey, Jo, this book could lose a couple hundred pages and not miss them."
So, I didn't like HP4 and I liked HP5 less than I wanted to, mostly because I thought they were just too long, too shambly, too much to keep track of.
But with HBP, I really thought she got a hold of what it takes to have a strong narrative through-line in a book that long, more or less. Deathly Hallows, though, boy, it's got enough narrative drive to power a steam train. Even the slow parts feel like they work because the action is so intense -- you need a breather. Rowling will still never win any awards as a stylist, vivid action notwithstanding, but this pulled me through 700-plus pages faster than I can ever remember reading a book, and I read fast. Color me impressed.
I loved the Dickensian scope of the thing, and really, Dickens isn't a bad comparison to Our Jo. Vast, vivid casts? Wide-ranging stories? Humor and grimness both? Check, check, check. The primary difference in their storytelling of course is that Dickens is a social novelist for adults, and Rowling is writing fantasy for kids, first and foremost, so we get moral advice where we might have had social commentary. (Though the Ministry of Magic and its employees are a form of social commentary in and of themselves.)
I loved how many places and things from the earlier books came into play -- it helped create a real sense both of the scope of the adventure, and really made the story feel like a conclusion, not just a last chapter. It's been so long for me since I read some of them that it's like a little chime going off -- oh, right! The basilisk tooth! And I loved that everyone had a part to play in the end, even Sybil Trelawney, and was hella impressed at how many characters she had me really invested in. (Though I will admit to having stopped at one point to count Horcruxes on my fingers.)
I loved how many of the characters we've known for ten years got to be heroes, that Neville was a badass and Luna could resist torture, that Dumbledore was posthumously revealed to be a much more complex man than Harry had thought, and that Snape got an even better final vindication than quite frankly I was expecting. He is, in some ways, the most moral of the adult major players -- loyal, trustworthy, brave, as well as petty and arrogant and extremely bad with people. (Sorry, couldn't resist.)
Having just reread "Transfigurations," I wanted Draco to be redeemed, dagnabit, but his behavior here was perfectly in character and kept him as Harry's mirror image: surrounded by family love and care, but unable/unwilling to reach out and do the right thing for anyone else.
The Nazi references were as always more than a little heavyhanded, but Voldemort and the Death Eaters felt really vicious, really threatening, in a way they don't always. I thought having that early attack on Muggle territory was a smart move: it makes it realer for the readers, having our heroes attacked in a coffeeshop on the Tottenham Court Road.
And our heroes -- man, Harry, Hermione, and Ron all outdid themselves here. I was betting Harry would have to die and come back, so none of that surprised me, but the bravery and dignity with which he went about doing it was both believable and impressive, and it made me as angry as Snape was to learn later that Dumbledore had planned Harry for death all along. About the awesomeness of Ron overcoming his demons, enough has been said, but both he and Hermione were fantastic, and the bond between the three of them was affecting and believable.
I was actually really upset by Fred's death, because I felt like the Weasleys have suffered enough already, but I guess they are the family we know the best and they end up paying for it. I gasped when I realized Remus and Tonks were dead. And while I didn't think much of Dobby earlier, I was delighted when he showed up to save the day, and moved by Harry's insistence on digging the grave the old-fashioned way.
And yes, love doesn't conquer all, but I really did like how much people's love moved the plot forward. Kreacher loved Regulus. The Malfoys love their son. Harry loves his friends. Snape loves Lily. Even the Dursleys love Harry, sort of. It's been a theme throughout the series, but I liked seeing it come front and center in the closing chapters.
Which is also why I don't mind that the epilogue tells us nothing about anyone's life outside of family and friendship bonds -- in the world of Harry Potter, that's what matters, not what you do. I thought the epilogue was kind of lame, but also exactly the sort of thing one would write for oneself working on a series like this one. It goes back to the editor point, but I'll give her a pass on this one.