I think Carlos Mencia is hilarious. His stand-up is funnier, but some of his bits are unexpectedly great. Like the time he tried to order a racial slur on a license plate. He himself was shocked by the reactions he got.
I don't agree he uses it to be shocking, that's just his humor, his perspective in comedy. The way he uses it isn't shocking either. And after two seasons, the shock value would have worn off already, but people still find his show funny. Chappelle is the same way. He constantly uses racial slurs and stereotypes for humor, but his audience obviously doesn't find it shocking, they just think it's funny.
I was happy when I found out Mencia was getting his own show because I remembered his stand-up very well. He had something.
Edit: By the way, he's from Honduras (One of the reasons he hates Latinos being lumped together as "Mexican" and "Cuban.") There's nothing fake about his heritage.