Oh my goodness. I don't think I've blasted through a book of this length this quickly before.
Again, the religious symbolism is pretty heavy in this book. However, I feel it's more action-oriented than The Golden Compass. Maybe it's because the one-on-one combats read better than the massive fight sequences of the first book. While there is still some world and character building, the universe of "His Dark Materials" has now been well established so that the reader can jump right into the action without having to understand why choices are being made.
My only negative feeling towards this story is that it jumps around a lot. There are many different characters who are following their own paths that we're interested in. In the end, it all comes together cohesively, and ready to tackle the next big thing. The Subtle Knife is not a stand-alone book by any means, but a good solid second book in a trilogy that inspires its reader to pick up the third installment, The Amber Spyglass.