Okay, to just give my opinion.. I've seen the movie twice now, in different theaters. One was really big, with a terrible quality (compared to others) and one was smaller, but dolby digital, it was beautiful
First of all, seeing all things they added.. The millenium bridge collapsing, it was unbelievable (especially when you think of the fact the bridge is still there) and they did a really good job on this scene.. It brings some questions to the audience, I think, like; why Olivander's? It also shows how the muggle, and wizard world get more and more strangled with each other (right word?)
After the dark scene and rollercoaster of flying death eaters, we get the part, I believe, covers most time of the movie: Professor Horus' memories. Dumbledore already gives us the hint of the Hocruxes, with his hand looking creapy.
As on the other hand, I kindoff really enjoyed the humor in the 'romance' scenes; let's not forget we're seeing the same actors and characters in 8 movies, so I think it's really good to share some teenage-problems of them with us, since they're in that age now. In the first, not so good theater, everyone was laughing, and I enjoyed the movie as a comedy, more as a Harry Potter film. The second theater however, was not so laughable, and sometimes a small laugh about Ron's stupid comments was all. The fact maybe that this audience was way more silenced, and focused on the main story line made the movie a bit darker, or interesting for me.. At least, it seemed.
The final scenes were indeed, a bit short. I do like how Malfoy was shot in scenes through the whole movie, it adds questions like 'What are his intentions?' Besides, Professor Snape has this as well. In the second theater, the moment that they entered the cave, was already scary. Everyone was full focused, which made me very nervous, although I read the book like 10 times, and the movie was seen before. The scene of Dumbledore drinking the poison, with the dramatic music, till the moment that Snape 'betraits' him, made the audience's eyes all clutchered onto the screen (God i'm so bad in english) In the end, I even heard some tears falling when Dumbledore lay there, with Harry on Ginny's shoulder.
My opinion is that this is the best of the Harry Potter movies, since it really focuses on the main story line going through all movies (although it kindoff started in part 4)
I must say, that Rowling did an amazing job on this, thinking about it.. The first 3 movies looked completely useless to me, but besides the development of the main characters, more and more elements keep coming back, and you'll feel sorry if you missed one part..