Agatha and Sophie both know their place. Sophie is beautiful and makes sure to do good works. Agatha is ugly and lives in a cemetery. When the two are taken to the School for Good and Evil, it seemed clear how they would be sorted. 
 School is clearly written for middle grades, which I hadn't realized when I started. Even so, I enjoyed the writing style and found the plot compelling. 
 The "twist" that Agatha and Sophie weren't really put into the wrong schools was fairly obvious from the outset, even before they are taken from their village, though I struggled to find why they were the only ones who seemed to have been sorted by inner character rather than outward appearance (Tedros certainly fails to act like a Good and Dot seems rather out of place among the Evils). It makes sense given the final reveal, but little sense within the context of the story itself. I also felt that the purpose for the switcharoo (I don't want to give too much away, but it has something to do with the School Master) felt a little cobbled. 
 All in all, I did really enjoy it. I'm looking forward to reading the sequel.