How bad is it? It's one of Doris Wishman's better films (utter dreck).
Should you see it? If you really want to see a penis-transplant film and "Percy" isn't available. No... not even then.
This is a version of the oft-filmed "Hands of Orlac" theme, where a killer's hands are transplanted onto someone, turning him into a killer; the variation here is that a penis transplant turns the guy into a rapist. Someone once wrote that Wishman directed films like she'd never seen one (in fact, she rarely did watch films); she also made sex films like she was alien to the concept of sexual attraction. This one has a golden earring fetish. The transplant of the title is supposed to be a surprise, but it's IN THE TITLE. Meanwhile, you can spend the 70 minutes of the film wondering why Wishman shows static shots of her carpet or shoes or sidewalk (did she always look down?) and why we hear conversations only as overdubbed reaction shots. Otherwise, it's just ugly naked people... and no penis is shown, though that seems to be the reason for the film to exist.