Acting. I think everyone really upped their game for both films so I've really nothing bad to say about it.
Transition from book to screen: I thought it was done very well, in fact it felt exactly like the book, the first two thirds of the book feel very plot and story based, the last third feels all action and that's pretty much the way the transition between the book to film felt, it was all action with some plot but very enjoyable the way it was done.
Gringotts: Very well done I thought. I loved Helena's acting of Hermione as Bellatrix, it was fantastic, you really got the sense that it was Hermione and not Bellatrix, Helena played that part down to a tee. I also liked how the envisioned the Gemino curse that's pretty much how I imagined everything would multiply too
Ron and Hermione's kiss: Very corny with the cheesey music and whatnot but entertaining at the same time, I think it showed the tension that had been building up between the two characters for such a long time and when they laughed at the end I got the impression it was like they were both saying "I've been wanting to do that for a very long time"
Nineteen years later scene: I really enjoyed this, I know some people have said their make up and stuff wasn't well done, but it was ok in my eyes and didn't take away from the scene. Replaying the ending music piece from the first film when Harry finished his first year at Hogwarts evoked this great sense of nostalgia and felt like everything had come full circle.
I loved the way they portrayed Neville finally getting his moment and how its him Harry tells at one point to hold the fort, its pretty much like the book, just shows you how far Neville has come.
Final Battle between Harry and Voldemort and the aftermath: If there's one criticism I have its the way they did it. In the book when Harry and Voldemort are circling one another in front of everyone and the speech that Harry gives about the elder wand and how Voldemort has never understood love I was on the edge of my seat and reading as fast as I could to get to the end because it felt so exhilarating, you felt like you were there and you could feel the tension and climax of the scene.
But the film felt so anticlimactic, it was very enjoyable to watch but just not the same, it actually feels quite forgettable compared to some of the other fight scenes in the film. The bit where Harry says in the book he's the true master of the Elder Wand and then the sun hits the Great Hall it was one of those scene I could envision working incredibly well as a film version and I really wanted to see it, so I was quite disappointed that it and the scene in the great hall as a whole wasn't there. I think that whole scene should have been kept the way it was in the book as the very final climactic last battle because it works so incredible well.
As for the Aftermath: I just didn't get that sense of joy and excitement that everyone had in the book when Voldemort has finally been defeated compared to the film. In the book you just get a massive sense of celebration, I couldn't stop smiling during that part in the book and it just wasn't there in the film. I did however really like the scene with Harry, Ron and Hermione and the three of them talking outside the castle, it was very heartwarming.
I would have liked to have seen Snape's past with Lily shown more in the film as its so important in the book, however I loved the bit where it showed you Snape cradling Lily's dead body and where you see his patronus there was something very moving and emotional about those two bits, they really brought a lump to my throat.
