I think that a major part of what Ben Stiller tries to do is to portray characters who are absolute jerks, in a manner meeant to ridicule the foolish character, not to hold him up for emulation. (Example: the vain and clueless male model in Zoolander.) Now, whether he's entirely effective, or even enjoyable, is another question.

Not having seen the film, but having seen excerpts in the context of way-too-many TV commericals, I believe that when these characters speak the word "retard," especially when they do so excessively and repititiously, the audience is supposed to realize that they are inarticulate, lack imagination, and are probably more lacking in mental acuity than whoever they are seeking to ridicule.

I'm not crazy about Stiller's work because most of what I've seen is heavy-handed and obvious, and therefore less than funny. I certainly understand everyone who is sattuing their intention not to patronize this effort ~ I won't be in attendance, either...

Now, I do like Jack Black. I was put off by him at first ~ anyone who is that full of, er, I mean, sure of himself usually makes a very poor first impression upon me. When my kids pleaded his case ("Dad, he's really funny!") I didn't listen, but they sold their mother on his virtues, and then she in turn convinced me. Just below his blowhard surface is a very sweet quality that, along with a genuinely sharp wit, is the basis of his appeal. As Little Hawk mentioned, he's very entertaining and likeable as the central character in School of Rock.

Plus which, the sunnavabitch can really sing. Check him out in his breakthrough role in High Fidelity: All through the film he portrays a loud and egotistical entry-level-employee type, someone who can never be taken seriously. Then, at the very end, he reveals his surprising musical talent with a bravura rendition of Marvin Gaye's "Let's Get It On." For a tubby little white boy, he sure has got some soul!