The food can vary from ship to ship and even different cruises on the same ship. A lot depends on the on board chef. I love HAL food, enjoyed the NCL Dawn food in the main dining room more than the pay-extra restaraunts, and usually am very happy with Carnival food. Our last time on the Dawn (last Dec.), I thought the entertainment was the best I had seen on a ship. Just got back from Carnival Legend, and the decor was much more sedate than usual. Entertainment was good, but not great. AND, there were more elderly passengers than I have ever seen on a HAL ship! Things just vary from cruise to cruise. I always try to find the things that I like on a given cruise and I try not to generalize. But, that said, over all, I have better impressions on HAL, NCL and Carnival than other lines....based on multiple cruises on may lines.
So, I'm afraid that you should go ahead and do lots of pre-retirement cruise research, but then be prepared to do more after you retire!