I've done two small ones with P&O and loved it.
Food :I was very pleased. We did freedom dining so could come and go to the formal restaurant as we liked.
I really enjoyed the black tie night - sauntering about looking at the outfits was fun.
The entertainment - SO impressed. Absolute professionals doing several different shows every cruise, with smaller things like singing duos, pianist, harpist too.
I enjoy talks, demonstrations, history, literature, all were well represented.
The cabin - we went utter basic. Our choice. Two narrow beds, a teeny shower/ loo room, wardrobe and desk. I would love to try the swanky suites but we were practical money wise.
The people - both were child free. Our preference. So generally an older age group, no problem with rowdy groups.
Things to do - several pools on each, including a little one in the stern of the ship I don't think many had noticed, with its own bar. A very civilised library. The crows nest piano bar. Gym and beauty salon, tho you pay for those.
Excursions - did a couple of coach trips, felt a bit works outing to Clacton, but well run. I most liked when ship docked right inside Norwegian harbour town and you could just step out and you were there.
Constant sense of slight anxiety that the thing might sail off without us, tho!
Not a seasick moment either time.
I'd jump at another one.