While this book was clearly better written than the first three, the plot took too long to get started and the ending was rushed. The heavy emphasis on the romance aspect didn't help matters either because Clary and Jace not catching a break is getting real old, real fast.
I did enjoy the fact that Simon was more of a main character in this book though and the added POVs of Magnus, Alec, Izzy, Maia, and Jordan were a welcome break from constantly having Clary and Jace angst over their relationship.