I voted for 14 @POFQ. But I guess it would really depend on what time of year you were thinking of going! When its busier, the extra time comes in handy so that you can have more breaks from the parks to do other things (swimming, golf, shopping, spas, etc). If you go during value season, then upgrading your choice of hotel and the smaller crowds still gives you plenty of park time and time to do other things!