I've actually made that mistake in the past! We always book an inside, (except on Spirit Class, where we sometimes book a 4K cabin) and have been given an "upgrade" to an obstructed balcony, in a poor location on the ship. I'll keep the inside in the future! A couple of times, we've been upgraded without any O.K. from us, and in that case, there's not a lot you can do. We enjoy the quiet, serenity of the inside cabins!