No, I didn't like it.
I have two theories.

Theory #1: (the more likely)
JKR wrote a rough draft of the ending years ago.
Through the other six books, her style and plot devices grew up and became more sophistocated.
In the end, she felt obligated to tie it all in with the original plan, which remained a little weak.

Theory #2: (the charitable one / benefit of the doubt / hope against hope)
She has intended all along to write an eighth book, but she wants us to believe for now that the seventh book is the end.