Menus are different. Food opinions are very subjective, but I prefer the food on Princess for both variety and taste. They have pizza (pretty good IMHO), but not 24 hrs unless it's changed recently. They do not have the self serve ice cream. You can get ice cream in the dining rooms and in the Horizon Court late in the afternoon. They also have a Haagen Daas stand (for a fee), they are usually open from lunch to dinnertime I think. I don't mind paying the extra I see something that I want.
I think you can purchase a card for the ice cream... at least I think I heard that. Don't know for certain though. There is a grill ~ hamburgers, hot dogs, chicken, fries, etc. We enjoyed it.