While it is an amazing album as far as art goes, is serious, and doesn't try to cater to what soulja boy and Lil Wayne call hip-hop (more aptly described as pop), it is FAR from being positive. I think the album is a very thoughtful—though not direct— examination on growing up in America and staying true to oneself.
I also applaud this album because gives exposure to some other more traditional-sounding genres like Trip-hop, Soul, and Indie Rock. It separates itself from the bland pop music that really pollutes our society.
If your kid is as much of an "old soul" as I was, they will enjoy this album and understand the deeper, more abstract ideas Kanye is trying to convey rather than focus on his profanity or hedonism. Don't underestimate their maturity otherwise you can really hold their development back (this is coming from a psychology major). Of course, in the same breath, don't overestimate it either. I think the most important message Kanye tries to convey is to grow up well but to not kill that which makes you young and naive because it is a necessary in adulthood. It's the same message Taylor Swift conveyed in her song "Innocent" about Kanye.
Here's one more thing to think about: the famous Chinese philosopher Confucius was a moral genius and was a very good judge of character but was so jaded and painfully truthful because of his harsh childhood that he didn't live to see his work come to fruition. I will end with a famous quote from Picasso whose cubist philosophy influenced Kanye: "Good taste is the sworn enemy of creativity."