Depends on what's important to you....quiet? Quick access to elevators? Remember that 14 is right under the pool deck, sports deck and teen club, so while it would be a quick hop up, it might also be noisier. Kids clubs are 14 forward. 12 and 11 are both all rooms with just rooms above and below, so would be quieter.
There are no midship elevators on the Allure. There is a fair amount of separation between the elevators and the rooms, so no noise worries there.
As far as fore versus aft, that mostly depends on what you want quick access to via elevator. Main theatre, Starbucks, spa? Foreward room. Aqua theatre, Boardwalk, Windjammer? Aft.