While Izzy was no Sophie and Dex was no Archer, I loved both if them lots. Izzy was fun and Dex made me laugh frequently. I also enjoyed learning more about Torin, a centuries old guy in a mirror, who also had me laughing despite the fact I had huge trust issues with him. 
 One part I liked was that Dex's story was unpredictable, some of his secrets came out (some even he didn't know about) and I was just, like, "woah, did not see that coming"! Also, some of the other friend's Izzy made were fun, although they didn't have any of the cool magicky stuff Dexter did. 
 The story was quite short, and moved very quickly. I am pretty sure I finished School Spirits in only a couple hours. Also, this book seemed a lot lighter than Hex Hall. I think the circumstances were more dire in the Hex Hall trilogy and Sophie seemed much older than Izzy. Plus, I think I got Sophie's humor so well, and with Izzy, well we just have different personalities! Still, the book is laugh-out-loud funny. I do love the Hawkin Sarcasm, as I have said before. 
 I enjoyed how the family aspects were handled. Izzy is part of the Brannick family where she is taught to fight and fend for herself. Her father, however, is absent and her mother is more like a trainer most of the time. Also, Izzy's sister is missing. The point is Izzy's family is a little strained and hanging out with her first friends at school is good for her. I also loved the character growth between Izzy and her mother. 
 Hauntings were very intriguing in this book, ghosts and spirits are another specialty of Hawkins. There is a lot of foreshadowing before the actual spirit events, though. This was kind of cool, as we got to spend more time with the characters and got all these clues to the mystery, but then again Rachel Hawkins always makes a good ghost and I would like to see more of each!