So I've seen it. And I loved it. OK, I'm always rather satisfied just after the first vision of a Potter movie, so maybe six month later I will be less indulgent but it was a great moment.
The movie isn't perfect. We can feel in the beginning that in fact it's just a half-movie as the first part. But after the action rarely stops but it's never too much. Some changes are interesting, some others aren't (McGonagall, ordering to lock the Slytherins into the dungeons? Children, even some of them are pro-Voldemort? On a future battlefield? No way!) and there is some plot holes. Wormtail apparently fell in one of them.
It would be too long to list all the great things. It's spectacular, readable (no comparison with the pursuit in the forest at the end of HP7 part 1). The dragon is magnificent. Sick and superb at the same time. The actors are perfect or almost perfect (well, if you didn't like Fiennes' Voldemort before, I don't think it will change suddenly but there is no dissonance in the young actors acting and Alan Rickman, Maggie Smith... All of them have "their" scene).
But the best thing, the most moving thing was Hogwarts. The school is a real character in this movie. In the other movies directed by Yates the castle was austere. No ghosts, not many talking portraits, it wasn't the magic castle of the beginning and it was justified by the story. When we rediscover it at the beginning of the movie, it 's downright sinister, a prison. So when the Order takes back the control it's a real happiness to see Hogwarts live again, getting ready to the battle. Then to see the sets that we know for ten years be destroyed was epic and heart-rending at the same time.
So now it's finished and it finished on a good note. The movies had many defaults, the books are way better but at the same time to see the actors grow up, to come back to this universe almost every year,that was something.