Hi,
I've owned the AP Centuries and Calderas, and have the Khorus X in my home now. All are exceptional speakers but have very different balances and strengths that would make personal experience mandatory before purchase. This isn't about bad and good here, it's apples and oranges.
The Khorus, and more so the X version possess a dynamic prowess, timbrel verity and sheer power that AP speakers cannot quite equal.
The Centuries and Calderas lay-out simply inspiring sound stages and more aptly convey transparency and focus through the upper mid.
The Khorus are the kings of rhythm, pace and timing. The way they stop and start notes--with authority and speed, sends a shiver on some recordings. The AP's recapture fine detail with aplomb and are spatial giants but miss "some" of the body, or fundamental structure of a note-- you don't *feel* the music in as many dimensions as through the Khorus.
Ultimately room size, listening preferences and system make up will determine which of these speakers will suit you best. Never make a buying decision based on I-forum feedback. IMO though, both those speakers belong on your short list for home audition. FWIW