Wow, the first half of the book is such a raw look at the tearing down of a man. Each betrayal, slight, and punishment painted a full color view of Acheron. It was well worth the emotional discomfort of reading 300+ pages of constant suffering to understand the beautiful depth of character that resulted from his journey through hell.
As rich and profound the first part is, the second part is shallow and mediocre. After so much pain, I was waiting for a delicious regrowth of overflowing joy for Acheron. I wanted to see a slow building relationship in which faithfulness and loyalty was proven time and again. And like his arduous descent, the ascent should have been equally rewarding. Instead what I got was meh.
I think his long-time friendships with other dark-hunters were supposed to be part of that growth and proof for him, but I just felt like it wasn't detailed enough and the romantic parts were just plain sparse. Maybe because I haven't read all the books in between I am missing a lot of subtext. I'm left feeling like Acheron deserves more.
Let me say this, this series has always been fast food reading for me. It's not the best quality, but it's fast and easy and satisfies my craving. I was surprised by the gourmet quality of the first half of the book, whereas the second half lived up to it's fast food reputation. Four stars for a gripping first half and some amusing bits in the second. Still probably the highest rating I've given a book in this series.
Update 9/25/2011: I have re-read Acheron in the proper order of the series, in which I now understand the importance of this book. The story felt deeper since I knew the history of the other characters. I still stand by my wish that Ash had a more detailed romantic/win his love part of the story to counterbalance his sorrow and suffering.