Some movies age very well and seem timeless. Others, like RAIN, seem pretty silly when viewed decades later. However, on a purely "camp" level, Joan Crawford's performance is well worth seeing as the tramp with a heart of gold, Sadie Thompson. She is indeed "trampy" in this performance and lacks any subtlety whatsoever--probably not a bad thing considering the character she plays.
The movie is a morality tale about a hypocritical preacher and his dried up old wife. Both are nasty and self-righteous, though down deep the preacher (Walter Huston) is ALL MAN (hubba, hubba)! Please,...this seems less like real people but more like broad caricatures--which, when you watch this hoary (it means "old", not "trampy" once again) film, that's about all you get. An interesting curio but hardly a film to get excited about or that will make any lasting impression.