If you have arthritis or other problems climbing a ladder and climbing over someone in the dark sleeping, without waking them, sleeping in the overhead gets old. Sleeping on dinette cushions or a jacknife couch is not for light sleepers. Youngsters can sleep nearly anywhere. A rear bedroom and RV Queen bed is essential for most "mature" RV'ers which pretty much requires a rig over 27 feet in length. Not a lot different than driving a 24 footer. Plus!! you get more interior and exterior storage space.No need for bags, boxes and clutter in the aisle, in shower stall, or in the overhead.
Been there!