This report compares the Hardcore-version to the original version.
Not only are the versions differently cut, there are more differences. The HC-version features a blue filter in several scenes (which is supposed to make it look like the scene was shot at night), the original version misses this. The title is different as well - The German version shows "In der Gewalt der Zombies" (loosely translated: "Caught by Zombies") while the HC-version is named "Sexy Nights of the Living Dead". There are slight differences concerning brightness and colors (skin tones, too), but it is hard to name one of the two versions the "better" one.
All in all 672.8 seconds (ca. 11.25 min) are missing, 13 cuts altogether.
Runtime of the Hardcore-version w/ credits: 1:51.43 min.
Runtime of the "Original" version w/ credits: 1:40.30 min.
Runtime designations relate to the uncut version.
The prostitutes take their clothes off before they enter the shower.
The next scene inside the shower is longer in the HC-version as well. Mark gropes one of them, while the other takes care of Mark's penis first with her hands and then very shortly with her mouth.
The sex scene in Mark's room is completely missing in the zombie-version. First, Mark takes care of his two playmates orally, then it's the two women's turn to take care of Mark orally, finally he has "normal" sex with a lady. The scene ends with Mark ejaculating.
The sex-scene on the ship misses a close-up shot of Luna (Laura Gemser) touching herself.
The tracking shot across Luna's body continues, she keeps on touching herself.
Mark orally pleases his neighbor, Dirce, longer.
While the zombie-version cuts to the scene on the boat (different color-filter compared to the HC-version's, by the way) directly after the next shot, Mark is again longer busy with his neighbor in the HC-version.
Luna continues "dancing" by shoving the bottle of champaign into her vagina.
Luna continues "dancing" with the bottle.
More of that...
Luna pulls out the cork with her vagina.
Mark is being pleased orally by Dirce on the boat, his back facing the camera. Nothing shown which would deserve the attribute "Hardcore".
Luna and Dirce make out longer on the beach.