This was much better than the trailer let on. Yes, if all the shyt about them exaggerating Shirley's estrangement from black culture is true, they did him somewhat wrong, but I don't think he was that misrepresented. He was shown to be a proud man who was caught between cultures but felt strongly about putting himself out of his comfort zone to try and enact change.
Either way, the movie as it is works, regardless of how true or not true to the facts it is. Farrelly got a good balance between the comedy and the drama and Viggo Mortensen and Mahershala Ali got great chemistry. Both did amazing jobs with their roles.