I think only euros disregard this film.
As someone who hasn't lived in either New York or Europe, the classy urban environments with an Al white cast set in the cultural peak of society is insanely comfy. Everyone dresses up, Corso just drinks, smokes and reads ancient magical texts in sexy European libraries, and his lodging his provided by a billionaire financier. He has a sexy demon body guard protecting him, he's uncovering secret societies.
It has the same appeal as James Bond, just with occult mysteries rather than spy thriller shit.