Brandon Sanderson has read the final Harry Potter installment. He had, in part, this to say about it:
bq. Initial thoughts: I liked it, as I’ve liked all of the other HP books. However, it lacked the charm of the books that occurred inside of Hogwarts. (Source: “Brandon Sanderson”:http://www.brandonsanderson.com/blog.php?date=1187247600)
That, for me, was probably the main thing about the last book that I disliked about it. I missed the uniqueness of Hogwarts and the interactions with the students and the teachers. It made sense that something near the end would have to take place away from the school, since Harry had to explore his roots in order to understand better how to defeat Voldemort. It just would have been nice to spend a little more time at the school. I didn’t really expect much of the story to take place there, though, since the conclusion to Book 6 made it pretty clear that Harry didn’t intend to go back for his last year.
I’d still love to see some sequels to the series to fill in the years between Voldemort’s demise and the epilogue. Whether Rowling decides to break her word and actually write such books, however, remains to be seen.