Given the amount of people that have read/will read this book and therefore the gazillion reviews that have been written/will be written, I'll keep this short. 
 I was disappointed with City of Fallen Angels. I loved Clare's last book, City of Glass, and I'd hoped that this book would be at least as good as that one. 
 It wasn't. It started off slowly, with an irritating OOC Simon, and just when things were getting interesting (and Jace and Clary were getting hot and heavy), the book went...dull. 
 The characters were annoying, flat and overly cliched - and can someone explain to me why did everybody had to end up with somebody else? I get that love is the strongest thing and all, but seriously, I thought I was talking with a dating agency. 
 And what about Alec and Magnus? They did that little cameo at the end of the book, they fought and fought and then it was all over. I believe they're the cutest couple ever and their absence just had me loathing the author for (a little more than) a while. 
 I also missed Jace and Clary's relationship as it was in the first three installments. It just felt so real there, whereas it couldn't even be called a relationship in CoFA, they were either avoiding each other or hooking up. 
 One of the biggest flaws? Sebastian. 
 He was dead. D-E-A-D. Morto. Kaputt. 
 I didn't want to hear anything more about him, and here I'm stuck with him for at least two other books. 
 Also, the whole plot wasn't that good. It felt like it had lots of holes and imperfections, and my mood couldn't forgive that. 
 The only positive thing was Isabelle: I liked how her character is evolving and I hope the author won't make a mess with her too. 
 I'm still hoping for the next book to be amazing and absolutely mind-blowing, but I'll try my hardest to keep my hopes low. 
 Update 06/14: 
 If I have to be sincere, this book (in my humble opinion, of course) doesn't deserve three stars, simply because it felt like the author wrote this book just because she was sure a lot of people were going to buy it. So, even though it was ok, or, well, meh, I could honestly say that my actual rating is 2 stars.