I'm going to repeat a bit of what I said about the previous book: I wish I had read all three books back to back.
This is a case where I feel like it's not three books, just one long story divided into three books. In fact, in this book, there's at least one character that you haven't seen since the first book, and you either need to have a phenomenal memory (I had to dig in my brain to remember) or have just read the book not long ago to have it fresh in your head.
So yeah, if you want to read this book, go read it immediately after the second, which you should have read immediately after the first.
I do love this series. It's so dark, so gritty. There are no truly happy endings anywhere, and shit just goes down and feels more real than in happy-fantasy-epics where everything ends up OK, the hero gets the girl, and unicorns fart rainbows and crap gold and everyone is happy. Not so much here, and I appreciate it.
It gives us decent endings for all of our main characters - some of them more open-ended than others (Ferro, Logen). I really liked seeing how the main characters in the Union ended up (like Luthar, Glokta, and West).
The whole series was about interconnected power plays, and it was nice to see how the whole thing had been orchestrated by a small number. It was also great how some characters were just played by others.
I'll even admit to laughing out loud to some of the fun twists in the series. I think an overly optimistic and positive person might not like the series - it does get down and dirty (not just literally, either), but someone who appreciates the darker, more cynical side of life should love it.