The bunk beds are awesome for vacation. We will not have them at home so it is a real treat for my girls.
On the Disney Wonder, last year, we had a bunk and my girls, 5 yrs and 7 yrs, switched for the top bunk. This year, at AKL, my oldest, now 8 yrs, wanted the top bunk, my 6 yr old, did not want it.
My biggest concern is if they get up during the night, when it is dark in the room, to go to the bathroom; we told her to wake us... oh wait, my dh told her to wake him and he would wake me...
she did not wake, and we had no instances or issues or problems.