I have to admit that I wasn't really looking forward to Hawke and Sienna's book. I knew they were going to be a couple, but they didn't seem like the right fit to me. I am so glad that I was proven wrong! They were great for each other. Sienna was the perfect foil to Hawke's stubbornness. He had some hangups due to his parents' death and the death of his mate at a young age. Sienna had to work constantly to control the power of her specific ability. They've both been through a lot of pain in their past and I liked how both took the effort to make it work.
I really enjoyed the storyline involving the X designation and how far some members of the Council will go to get what they want. The love story involving Walker and Lara was a sweet touch as well.
Often when there is a lot of buildup to a couple over several books (in this case 9 books) the book winds up being a letdown. Not so in this case. Nalini Singh has a total winner in Kiss of Snow.
The book is a bit slow, I think it wouldn't have seemed as slow if we hadn't been waiting for this story for so long. She took her time revealing them as a couple, letting them get to know each other as a man and a woman, dating, and taking the relationship in slower steps. She also gives us a side story of Walker and Lara that we can also enjoy and a lot of progress in the Psy Counsel/Changeling conflict.
This book was so complete, so satisfying, I almost feel like it could be the end of the series. Doors are open, you can see new characters, new story in the making (and there is another book after this). But if you want a period at the end of a sentence, this book could be it. I've felt frustrated with a few of the books, like Singh had lost her way a bit, but this really left me with a satisfied smile on my face.
My only complaint in the book is that Nalini Singh has too many "S" names. Sascha, Sienna, both living in Sierra Nevadas. I kept getting confused!