My daughter and I had Cabin 5122 (atrium) on QM2 coming back from the tandem crossing on May 1, 2004. It is supposed to be the same interior size as the balcony cabins but I must be claustrophobic as we had hull balcony cabin 5200 in March 2004 to the Caribbean and I felt the atrium cabin was smaller than the hull balcony cabin. Nevertheless, it was fun to open the curtains and look down on the activities!