The Subtle Knife is a good fifty pages shorter than The Golden Compass, but I don't think that's why I read it faster (or why it felt like I did). There isn't much of Lyra here. The focus switches instead to Will Parry, a normal boy caught up in unusual circumstances. A lot of the mysteries presented in the first book are finally resolved (somewhat) in the second book, like the origins of Dust, and why Lord Asriel is hellbent in breaking the barrier into the other worlds. The pace is much faster, even if there are some tedious passages, and it fulfills its purpose of transitioning into The Amber Spyglass.