Okay, we all know the plot of a movie like this. Some sophisticated city folk go out to the country and are set upon by local inbreds who proceed to rape and kill them.
They retroed the movie to 1978, because if set today, the heroes would call for help on their cell phones and the story would be over.
This movie also had the worst set of fake and bad accents I've seen. Besides Gary Oldman effecting a British accent, we have the two women, whom you can barely understand. (Fortunately, the direct to DVD release has subtitles.
The movie is ponderously slow. The story is unoriginal and you don't really like the characters.