Well I have to say, I'm glad I didn't discard this series after the first book. Things got much more interesting and heated in "Dreamless".
The plot introduced several new developments, and really reflected the personalities of the characters. Of course, it was their inherent traits that brought about their ultimate downfall, but it was a lot more intricate than the first book. I love how we're getting to see more of the world and (view spoiler).
I wasn't entirely happy with the love triangle in the series. Helen fell in love with Lucas so quickly in the first book, and took this entire one to fall in love with Orion. However, it was really nice to get to know him better, he's definitely one of my favourite characters, and one of the most intriguing considering his titles. I can't wait to see what Angelini decides to do with him. The problem here is that I now feel like I know Orion better than Lucas, even though it's so obvious that she's going to end up with Lucas in the end.
Once again, Helen was pretty much insufferably annoying for the first 9/10 of the book. I get that she was going through a hard time by not eating or sleeping, but she was pretty ridiculous and some of her actions were just purely annoying. While Angelini seems to be trying to depart from wimpy Bella-like heroines, Helen only comes across as whiney, no matter how much effort she tries to put into learning new fighting techniques. By extension, I also found Lucas extremely frustrating in this book. Although (view spoiler) he is pretty one dimensional, and seems to be inspired by a weird mixture of Edward (staying away from Helen for her own good, but unable to; tortured) and Jace from City of Bones (unable to touch the girl he loves because he thinks she is his sister).
On that note, how have none of the Delos' put together the dates between Ajax's death and Helen's birth? At least in City of Bones there was some pretty concrete evidence that Clary and Jace were brother and sister no matter how badly you wanted them not to be. Here, the reader already knows that Lucas and Helen aren't cousins, since her mother fully admitted it at the end of the first book. What the hell? Since the mystery is already gone for the reader, this is just a really irritating plot development. I hope this ridiculous plot is tied up soon and someone comes to their senses.
Pretty excited to read the next book to see (view spoiler)