I understand they changed a LOT between the play and the movie version-- probably a LOT more than the Lugosi version had. One could say the Langella fim is the closest-- more or less-- to being a (SORT OF) "remake" of Lugosi, as both were based on the stage play, and both starred the then-current star of the stage play. And both were from Universal.
Still put in context of the times, it's fascinating to compare it with the Jess Franco version with Christopher Lee, the Dan Curtis version with Jack Palance, and especially, the BBC version with Louis Jourdan. That remains a rare case that proves one CAN do an INCREDIBLY GOOD film by actually following the book (for a change), and in my view features the very BEST Mina, Lucy, Van Helsing, etc. all down the line. Which makes it almost funny that Jourdan's Dracula is the ONE thing in the film that stands out as being VERY different from the book. And that's not a bad thing. To have been MORE authentic, it would have HAD to have had Christopher Lee in it. I often wish they had got him. But Jourdan's interpretation may be something that gives the film an extra level simply missing from what Bram Stoker wrote. Does seem strange to go so far to be authentic, though, and then go completely in another direction with the TITLE character.
You know, of all the changes in the John Badham / Frank Langella version (story structure, chronology of events, character relationships, etc.) I think watching it again the other day, the MOST baffling (and annoying) is probably, WHY THE HELL did they swap the names of the two girls??? Were they just TRYING to confuse people? Did someone just think "Lucy" was a better name for the lead girl than "Mina" ? ? ?
Of course, the entire personality of Mina-- SORRY, "LUCY"-- was completely changed in the film. In the book, she's the strongest, smartest character in the entire story. Even Van Helsing pales next to her (in fact, it's his secretiveness that helps result in Lucy's death, and Mina's NEAR-death-- that and the blatent sexism-- which was TONED DOWN in the BBC film, to make him a more likable character-- and thank goodness for that). In this film, she's flirting with the villain from the word go, right in front of her fiance, then goes to have what turns out to be a romantic dinner with him while her fiance is out of town (again, STRAIGHT out of the Dark Shadows feature film). And she spends more time aggressively trying to help the villain after than fighting him. Even the ending offends me now-- as it seems designed to SUGGEST (against all other evidence or common sense) that somehow, the guy has survived and will be coming back for a sequel, and the look on her face only seems to confirm this. (and again, just like the stupidity of seeing a BAT fly away from the spot Barnabas was KILLED in the DS film. W--T--F???)