Very readable and exciting. However, I have a few problems with the focus on appearance that is rampant through these books. First of all, there is a lot of description of the physical aspects of characters, which is rather boring and adds nothing to the story. It also doesn't really reflect the way most children do (or should) see the world. At one point Lucy comments on a characters eyes being too far apart - what kid notices that? 

The focus on George's weight is totally unnecessary. While fat characters should absolutely be included, it's not done in a positive way. And Lucy seems to be overly focused on her body and appearance as well, but not in a way that comes across as relatable, or could be a learning opportunity for readers. She uncritically hates on her body, and comments on other people's bodies, and hates on other girls. It's all very poorly done, and it's jarring to read in what are otherwise pretty fun books. I don't believe that these things should be glossed over in books for older kids/young teens, but the way it's handled in these books in particular felt icky.  

Also, the sarcasm and fighting between the kids is grating rather than funny for the most part. 

Basically it's difficult to read these books and forget that it's an adult male writing from a girl's perspective. 

But the ghost bits are so good, I'll definitely keep reading. If anything it will lead to some good conversations if my kid reads them one day.