I'm torn between rating it a three and rating it a four. I enjoyed the heck out of the book, but... there were things I didn't like. Didn't like at all.
We learn a lot about the world and characters of the series, which is awesome, but at times things seemed a bit forced or randomly picked just for this novel. Not because it is how Butcher planned it, but because a plot point needed to be explained. (that's what all authors do, i know, but... this series is much more than that)
Dresden showed some amazing ingenuity in this novel, more than he has before - by leaps and bounds. It's nice seeing him grow and learn. I also appreciated that while he has this nice boost in power, he still isn't superman. He still needs his friends and allies. And he still fears things he has faced in the past. For that I am grateful. Overpowered protagonists are the pits to read about. There is a point where you see that there are other people in this universe with insurmountable odds stacked against them as well, so it's not just Dresden being special. That was pretty cool too.
Character interactions were pretty great, but like the plot points, some of it seemed extremely forced - especially with how Harry was reunited with a couple people. (most notably Murphy) Dresden isn't the only one growing and being expanded on in this book either, we learn a great deal about many of the characters we've seen over the years. There's some really awesome stuff too - especially with Demonreach and Rashid. Rashid's pep talk, by the way, was probably my favorite exchange in the book.
Concerning a specific aspect of the Winter Mantle:The whole spiel about how easily Harry could rape any woman that was in the book was just disturbing and gross. I know it's supposed to be a part of the Knight thing, but there are ways to make a monster without rape being referenced continually throughout the book. One of the things I've always loved about this series is the lack of tacky romance and pointless sex. Things will probably get worse before they get better, but... I really hope Butcher doesn't push this too far, though, I'm pretty sure he already has.
And Cat Sith:He better not be dead. He was by far my favorite new character and I had hopped he would become a new sorta-ally for Dresden. Him being turned didn't really sit well with me. Sith was an incredibly powerful creature, I just couldn't see him being overtaken so easily. I don't think he'd dead, I'm sure he'll pop back up as the bad guy again, but I really hope there is some way for him to get himself back.