I never read the books - wizards and potions and all that is not really my thing, but I did enjoy the H.P. movies as they came out - especially the 3rd one by director Alfonso Cuarón (which was more adult and sophisticated in tone and imagery).
Warner Bros. absolutely got greedy by dividing The Deathly Hallows into 2 films: the first half felt draggy and heaped with exposition, whereas the grand finale Part II felt rushed and anticlimactic. It's great when filmmakers want to be true to the source material of much-beloved written works ... but so often they forget the adage that A Picture Is Worth 1000 Words. You can never convey the depth and nuance the written word allows, unless it is a line of dialog, all you can do is represent it visually. Sometimes you get lucky and a terrific actor conveys with one facial expression a whole chapter's worth of story. It is my sincere hope that Warner Bros. will release a combined and truncated version of Deathly Hallows as one 3 1/2 hour film ... it would work so much better.
My beef with author J.K. Rowling is the meek ending she gave the story. I guess she didn't want a bunch of crying children coming up to her asking, "Why did you kill Harry?" so she opted for a tacked-on happy future for the main characters that sets them nearly 20 years into the future. What was most perplexing is why the villain, Voldemort (played with his usual excellence by actor Ralph Fiennes), waited until his power was weakening to launch his final assault on the good magic of Hogworts and to have his final battle with Harry Potter.
As each Horcrux holding part of Voldemort's soul and power is destroyed by Harry and the gang, Voldemort grows weaker, so by the time Voldemort faces off with Harry in the forest he's down a few, and by the final battle at the school, his horcrux tank is empty. Lastly, whether written that way, a decision by the director (David Yates), or the actor's portrayal, when Voldemort faces off with his Goth army of evil wizards against the now seemingly-vanquished good guys amid the rubble of Hogworts, it is positively a ho-hum moment, when the full evil of the once human Tom Riddle (now Lord Voldemort) should have exploded into a gloriously vulgar display of mayhem. Someone this evil and now devoid of humanity should be cruel and vicious and a bad winner - wantonly murdering before settling down.
Instead we get a who's who of bit players having heroic moments (including everyone's favorite character actor Alan Rickman) and über nerdboy Longbottom (or whatever his name was) gets the big dragon-slaying (er, snake) moment with the magic sword. This Warner Bros. flick was really feeling like Disney toward the end there. And Harry and Voldemort's face-off? Voldemort goes limp in the middle of his money-shot and Harry's wand-bolt vaporizes the big bad man.
Oh yes, the best example of how books don't often translate to film is the whole bit with Who Controls the Elder Wand? I saw who used it and got a lot of exposition through the characters about who had possessed it, lost it in battle, won it in battle, and enjoyed its allegiance ... didn't care - what I saw mattered and I saw Voldemort use it and have it run out of juice at the end.
Too bad Rowling didn't have the courage of her initial convictions and had Harry Potter die - sacrificing himself to vanquish that evil, twisted Tom Riddle/Voldemort.