I have always loved Gordon Korman Books. I remember when I was in elementary school I enjoyed such classics as I Want to Go Home! and This Can't Be Happening at MacDonald Hall. Gordon Korman always seems to do a good job of portraying characters that are in school, and in trouble. The people in the stories always have interesting back stories.
This one isn't an exception, mostly. It has some interesting people, but I found them slightly less fleshed out than some of his other stories I have read. That could be because at 11-12 years old they just aren't as old as characters in some of his other stories. Also, given the books shorter length, there just wasn't time to develop them as much.
Regardless, I still enjoyed it. Lots of Kormans humour was present in the story, and it makes for a good read. He has a wonderful grasp of what is just absurd enough to be plausible and funny at the same time. The story progresses well, and the teachers aren't just caricatures. The mult-cultural fair that they present is vintage Korman.
I would certainly say this is a recommended read. It was light, but pretty good.