I agree with comments by rjsk23 about the consideration and care taken by Princess for passengers with mobility concerns. Harry travels with a small mobility scooter, which at home we fold up and fit into the boot of the car. On a cruise it allows us to roll on and roll off without worrying about booking it through baggage handlers as you must do when travelling by plane. It also makes getting around the ship easy - the distances are surprisingly long for people with mobility problems.
This was our fifth cruise with Princess and on each occasion we have been impressed with the service and care. On this cruise our cabin steward was particularly helpful and anticipated needs and helpfull extras - for example a blanket for an afternoon nap and a door stop to make getting in and out of the cabin easier. Those doors are heavily weighted.
The Shore Excursions Desk was as always helpful with advice on whether we should take the scooter ashore or use one of the wheelchairs available on board for shore excursions - wheelchairs are easier to manage on rough or sandy terrain, provided the pusher has the strength.
Our choice of cabin is dictated by the need to be close to the lift well. So far no problems with noise from passing traffic. We would not cruise unless we could book a balcony cabin - the french doors give a sense of space in the cabin itself. The Princess cabins do seem smaller than Holland America where we had a sitting area which we did like especially since we eat breakfast in the cabin. Storage is good - lots of hangers!