I read this aloud to my sons (14 and 12), and they both liked it about as much as I did. It's very well-written; Gordon Korman knows what he is doing, and there's a reason why he's popular/has won awards. 
 Donovan Curtis, an average-smarts kid, kind of a trouble-maker, suddenly finds himself being (mistakenly) sent to a school (The Academy) for gifted students. His involvement there and interactions with the super-smart kids start to change his attitude and who he is as a person. The reader gets to experience this through the point of view of many different characters, as each chapter is told by someone different (though many of them tell more than one chapter). This particular book mechanic makes for a more entertaining read-aloud time for the reader, so thanks for that, Mr. Korman. 
 The story is funny, sweet, and I especially liked the varying insights into the characters we get. A bulk of the plot (aside from the main premise) concerns the robot the Academy kids are building to eventually compete against robots made by kids at other gifted schools. 
 Geeks, popular kids, and kids of both average and high intelligence should enjoy this, and probably find someone to relate to. There are some stereotypes, though they are more amusing than mean, and they only serve to make some of the characters more endearing. A winner!