In general, there is much to complain about in the Harry Potter saga, but the beauty of the story (and a testament to Rowling's skills as a writer) is that I come up with all the complaints afterwards. While reading the book, I find myself almost unable to pull away and pick it apart.
I enjoyed the experience of reading this book and felt that, even though it did not need to be quite as long as it was, it was a good end to the series that swept the world by storm.
There is no excuse, however, for the epilogue.