I liked the quick beginning. No cosyness, no gemütlichkeit, just war.
With the marriage chapter afterwards Rowling kind of caught up on that. However, when the death eaters came, I found it somewhat relieving.
The whole long hiding and guerilla-warfare-part was the best. Especially when they sneaked into the ministry, but the stuff in the Malfoys' mansion was nice too.
The end was a bit too predictable indeed.
It was always obvious that our dear double-triple-multiple-agent Snape would under all his camouflage be loyal to the good guys, because such a great mistake just wouldn't have fitted to the dead father figure Dumbledore. And, hell, he was the doubtable twilight character since No. 1.
And it was very predictable that in the end, Neville would get a heroic part.
Nevertheless, the end was extremely tensioning and well-written.
The most surprising element of the end was surely that Potter and his two sidekicks survived. Since I have nothing against happy ends, only against too kitschy ones, that's alright for me.
Enough people died to not let it become laughable.
The epilogue was nice.