*DH SPOILERS* Thumbs up, and thumbs down
With few exceptions: tight and elegant. While some of the Hogwarts battle scenes were gratuitous and I agree could have stood with some editing, I was still on the edge of my seat throughout those final chapters. I appreciated several things: that Dumbledore was "exposed" as a real, flawed human being--quite a feat when the man had already died(!); that Hermione got much more "quality time" in this book (though Ginny and Tonks fared poorly quite above and beyond the Tonks/Lupin death); and that Harry finally demonstrated insight and maturity. As I charted in my previous blow-by-blow reactions to each chapter, JKR kept me guessing about a number of things--many of those guesses turned out to be wrong, which actually pleases me. I hate it when I can guess the solution to a mystery half-way through it.
As for all the Christian, Arthurian, Horcrux, and Hallows thingies ... I speculated in my blow-by-blow how those elements might harmoniously balance--and while I don't have a good eye for those details, I think they did. And these objects really do boil down to basic archetypes. So I didn't have a great problem with that. In fact, I appreciated how Harry himself got distracted and seduced by the Hallows, much as the Grail knights were seduced or way-laid.
As for Snape--of course he had to die (and yes, I'll say more about this anon). But I'm vastly relieved he was redeemed, even if posthumously. And call me a complete sentimental idiot, but I loved "Albus Severus" and then Harry's line immediately afterwards in the epilogue ... vindicating beyond all doubt Snape as the courageous hero we've always wanted to believe he was. That was the only part of the epilogue I liked, BTW.
But of course, staying stuck in Harry's POV was really frustrating at times ... especially since it meant Snape's terminal absence up until the very last minute. However, good news for fanfic writers and readers: the book is riddled (no pun intended) with so many holes possibilities that fanficcers can fix up imagine what else happened to their heart's content and not even have to go AU.
And yes: the epilogue was a let-down and oddly perfunctory. Why aren't any of the adult Harry crowd associated with Hogwarts? Why did they all get married and start having kids at 23 or whatever ... don't wizards live long enough to make it prudent to marry a bit later in life? This is JKR pushing her Big Message about the importance of true friendship and familial love. Nothing wrong with that, but I wholly sympathize with any criticism about lack of social diversity in this epilogue--not to mention a complete loss of her storytelling edge. She put on her lay-preacher's robes here and gave us a sermon.