The book was absolutely written as if you would read it cover to cover, and as a result many mechanics are in the wrong place when you want to use it as a reference. The inspiration/guide for the presentation was BX, which very much introduced rules in an as-you-are-ready-for-them format. Unfortunately (a) few players that buy ACKS read rule books that way anymore and (b) ACKS is a teensy bit longer than BX. So it didn't quite work as well as I'd hoped.
If someone is so inclined, it would be helpful to me if you started a thread mentioning the rules you find least accessible/hardest to find or learn in actual play.