Compared are the US Blu-ray by Scream Factory / MGM and the Uncut German Blu-ray by Anolis.
Mysterious Marcilla spends some days at the castle of general Spielsdorf and his niece Laura because her mother had to leave for quite some time because a friend is (allegedly) sick. Marcilla and Laura become friends. The latter suffers from terrible nightmares in which she keeps getting attacked by some huge cat. Day by day, Laura gets weaker until she finally passes away. Marcilla goes away for good. She then stays with Mr. Morton, using the name Carmilla. She and Mr. Morton's daughter Emma become friends. And just like Laura, Emma gets the very same nightmares and she becomes weaker day by day. The governess becomes a slave to Carmilla as well, the only person who gets suspicious is the butler. He assumes Carmilla is a vampire. With the help of some doc, the butler tries to save Emma.
The Vampire Lovers (1970) is the first part of the Karnstein trilogy and the only co-production with the US studio AIP tat is mostly known for Corman's Poe adaptions, the second and third installments are Lust for a Vampire (1971) and Twins of Evil (1971). The story is based on the novel Carmilla by Sheridan Le Fanu which had been adapted numerous times already - the most impressive adaption is Blood and Roses (Original Title: Et mourir de plaisir, 1960) directed by Roger Vadim. Director Roy Ward Baker had already worked for Hammer before, for instance on the incredible Quatermass and the Pit (1967) and later on also on Asylum (1972) for Amicus. The Vampire Lovers is well-staged with surprisingly lots of nudity (especially Ingrid Pitt should be pointed out here) and a lesbian context anything but subversive. The sex scene with Carmilla and Emma is just as memorable as the bloody decapitation at the beginning of the movie. For the Karnstein trilogy, Hammer adapted the classic vampire story to 70s exploitation. The mixture of horror, sex & violence works perfectly.
In order to get an R-rating, sex & violence was cut for the theatrical release in the US. According to the IMDB entry, the US Theatrical Version is available on VHS by Embassy. For its DVD release, MGM recontructed the missing footage - except for a small scene at the beginning of the movie. The first US Blu-ray was released by Scream Factory and is based on said restoration. The German Blu-ray by Anolis on the other hand contains a slightly longer version of the movie. At the very beginning, when the vampire is being decapitated by baron Hartog, the German Blu-ray contains an additional shot of her head hitting the ground. This shot is an SD insert though hence the (compared to the rest of the movie) bad quality. But there is no need to worry for owners of the US Blu-ray though, not really. Qualitywise, the US and German Blu-ray are identically equal, the bonus features are pretty are almost the same and the missing shot is so short that one can live with it.
US Blu-ray: 91:21 min
Uncut German Blu-ray: 91:36 min
The US Blu-ray lacks the shot of the vampire's head hitting the ground.