My husband and I picked this cruise specifically because my 12 year old daughter wanted to be on an Oasis size ship. The ports visited were St. Thomas, St. Martin and Nassau.
Ship:
Clean; big without seeming crowded; lots of places to hang out if you want a crowd or did not want a crowd. The only issues is that there are not enough deck chairs in the Solarium (adult area) and there is no chair policy so unless you are the type of person who doesn't mind 'holding' a deck chair starting at 7 in the morning (for the record we did not ever do this), you probably won't get a chair.
Too short of time to do anything.