The script is an unevenly good adaptation of the novel. It resolves better Dracula's aims and motivations through the love story. Also, it provides a more understandable glue to join the 4 men chasing Dracula from a XXth century point of view and removes unimportant characters having a more "round" story.
However, due to some changes certain parts are now incoherent since they were not properly adapted to the other changes. In addition, other parts are totally impossible to follow due to the amount of details only commented quickly along the movie.
Costumes and general artistic work is superb but it drives the movie to some extreme stravaganza that, in the case of the actors' performances make some parts of the movie completely overacted.
In any case, I think this is an iconic movie worth watching more than once.