Lulu is based on the same novel that G.W. Pabst's Pandora's Box was adapted from. Pandora's Box is one of the greatest films ever made so Lulu was bound to suffer by comparison. Both film versions tell the tragic story of Lulu, a vivacious woman, who attracts men (and women) eventually driven to desperation by their obsessions for Lulu.
Louise Brooks in Pandora's Box radiated sensuality. She showed no bare flesh but she had a screen charisma that made the audience believe that men would follow her to their destruction. This viewer would certainly have. In the film Lulu, the character Lulu is played by Anne Bennent, who spends a fair amount of her screen time naked. Yet, for all of her bare flesh, Miss Bennent does not have one-tenth the sensuality (or the acting chops) of a fully clothed Louise Brooks. For all of its nudity, the 1980 film is less erotic than Pabst's silent adaptation from 1929.
In addition to the more erotic aspects of the story, the film Lulu is less daring in other aspects of the story. In Pandora's Box, the character of Jack the Ripper is portrayed, like Peter Lorre in M, as a sad figure, clearly mentally ill. Fifty years later in Lulu, he is just an unrepentant psychopath (admittedly, one played by the dashing Udo Kier). The 1980 film may show a step forward in breasts and pubic hair, but it's a big step back in terms of emotional depth. Watching Pandora's Box I was moved by Lulu's fall. In the film Lulu I felt nothing at all.