One is a chrono with calendar, the other a perpetual. Depends if you want a chronograph - if yes, then choice over; if no, then choice over!
Aside from the function choice, the aesthetics of the two pieces are worlds apart. The RM is a modern piece - designed and built as such; the AP is more traditional haute horologies.
My best advice is see both, preferably side by side, and then make your choice on the one that best 'speaks to you'.
Good luck - and please post pictures here if you get your RM011
Andrew H