From what I have read about the movie, virtually everyone agrees that it is crude at best.
The crude humor will definitely appeal to many viewers; however, it is the cruel humor that makes the movie unacceptable. For example, in one scene, Borat is apparently invited to dinner. “Borat decides it would be polite to compliment two of the women at the dinner party, while he insults the third woman, the pastor’s wife, for being plain.” He goes to the bathroom and then returns with a plastic bag of his own feces.
In another scene, he goes to a Pentecostal church. “The worshipers scream in tongues and place their hands on Borat’s head, and he decides to respond in turn-- wiggling his tongue out and making ridiculous noises mimicking the worshipers.” Although the scene is a blatant mockery of the beliefs of the Pentecostal Church, I suspect that most of us will agree that this is a not-so-subtle mockery of the beliefs of all Christians.
The above quotes are from
http://www.themoviespoiler.com/Spoilers/borat.html .