It was an enjoyable book, not the best book I've ever written by any stretch of the imagination, but it feels good to have completed the series.
The middle parts were more tedious, but the finale was fairly nice.
I can understand Miriel's complaint about how all the stuff went down as it did, but I'm not terribly surprised. I've had trouble taking the Harry Potter universe's magic seriously, being a fan of fantasy books based on the D&D universes I'm used to well-defined magic system with a myriad of spells that I know the precise effect of.
While Harry Potter has many spells we know what they do, it still has a lot of, for lack of a better term, "really weird crap" that is never explained. I don't think the convolution didn't work so much as I came in knowing that explanation made sense in Rowling's head but will forever be beyond the rest of us unless she writes down exactly how her magic system works in intricate detail.
I didn't mind the epilogue, I don't know why you're all so upset about it. It could have said more, but it was a nice little conclusion piece to wrap it up and it worked.
I enjoyed the book, overall.