Went as a teenager with family and hated it - found it boring, not a lot to do, and the ship was quite Butlins’esque.
Been on three as an adult with my partner, and have two more lined up, and we love them now. We go with P&O and, unless the itinerary is something we are really keen on, go on the Iona ship wherever it is going when we are looking to book the holiday. We do round trips from Southampton and wouldn’t really be keen on flying to the cruise.
We went on holiday to New York last month with British Airways and the main thing that stood out for us was how much less hassle cruising is - it’s easy to embark and disembark and once you’re on the ship your holiday starts - no waiting at the airport, worrying about luggage weight limits, or being on a plane.