The movie was very disappointing if you want it to follow the book. There are several important characters missing, and a few key scenes omitted, whereas, confusingly, there are scenes added that hold no relevance to the plot as we know it from the book. Perhaps they are added because there is to be a different take on book seven?
However, if you judge the movie against itself, it was an enjoyable movie. The acting was far more believable, and the special effects were almost overwhelming if you were sitting at the very front in a huge theater.
Overall, I would say watch it if you like the movies, but if you love the books, you may not enjoy it. The Weasley Twins' shop was worth seeing.