Reading the reviews of this film on Amazon.com, the imdb and various other american-dominated arenas, you will see it described as 'a crime against celluloid' and the oh-so-elegant phrase 'it sucked'.
Having seen the film I can't believe they're talking about the same one I saw, because this film is very good. A lyrical, sexy and moving portrayal of working class masculinity in the foothills of southern France. The film presents three sections each dominated by one brother. In the first, Marc is presented as a drug-dealing thug on a path of self-destruction. The second presents Chistophe getting his life back on track after being released from prison. The third deals with Olivier, who rejects the world of crime that seduced his brothers and embarks instead on a passionate love affair with one of Marc's friends.
Compared to Morel's impressive earlier film 'A toute vitesse', 'le Clan' is less plot based and more concerned with character development. It has clearly been made for people of above average intelligence.
In conclusion, don't pay attention to the negative reviews. See this film and judge for yourself.