Overall we had a delightful experience aboard the Norwegian Epic.
However a few things to keep in mind if you have limited mobility:
1 - Rent a travel scooter before coming - this will give you full mobility on and off the ship.
Loved our cabin - only criticism is that with access to thermalspa, the jacuzzi tub wasn't used and took up room that would have been better served with a small table. However, our balcony was large and we spent most time out there unless sleeping or off doing other things.
We cancelled all our excursions after the first 2. Here in Cannes, we were able to take the scooter I rented off the ship and tour around the beautiful town on our own. We enjoyed some shops and delightful cafes while taking in the beach and sites of the harbor.