You cannot get a rollaway bed in all cabins and some ships do not provide them. But should you ever find any bed on any ship to not be to your liking, including sleeper sofas, simply ask your cabin steward to provide you with a 'topper'. Sometimes this will be a simple egg-crate type foam rubber topper, but other times it can be a memory foam-type topper.
Travel Agent/Cruise Specialist w/13 yrs exp and 48 Cruises on 11 cruise lines! Favorites: Paul Gauguin - Tahiti: Uniworld River Cruises - Europe; Celebrity Solstice-class ships; Holland America - 12-nights Baltics & Russia; RCCL - 14-nights Greek Isles, Turkey, & Croatia; Holland America - 14-day Alaskan cruisetour; 10-night Canada/New England cruise; 21 days Hawaii w/7-night NCL cruise; Oceania - 25 days in Asia; more than 3 months touring Europe by train. And many all-inclusive resorts!