Ann,
My kids have never strolled out the door at home so I understand it may seem foolish that I would be concerned about it on vacation. However, at BWV, the door to the hallway is in the room the kids are in. If they wake at night and get a little scared because they aren't in their own room/home, I really did worry that they may head for the door thinking mom or dad would be on the other side. My son had sleep apenea and woke up at night very scared on a regular basis. He just had his tonsils out 3 weeks ago and he has already improved 90% so he should sleep through the night. That wasn't the case when we were there in May.
As for OKW, for starters, we don't shut the door to the master bedroom. Plus, we leave a few lights on in the unit. In the past, when my son has gotten up in the middle of the night at OKW, he heads out into the hallway. At that point, he can see a living room and kitchen. I think he has time to get oriented a little more. At BWV, if he picked the wrong door on the first try, there could be trouble.
Am I paranoid?! Probably! But I can say that I have NEVER liked having the second door in the kids room and I know for a fact that I am not the only mom that has ever felt that way.
Lisa