We tried Princess and never will go back. Liked Carnival a lot more, although we liked Holland America more than Princess. I don't think you will find Princess upscale in the food department. Probably just a bad time, but we thought the food was terrible on the Star Princess and then Norovirus came and it was a mess. We just didn't have fun on the cruise and that's what we missed about Carnival. Even though we aren't party animals or anything, my 80 year old mother still wants to smile while she's on vacation and Carnival does that for us!
We have been on Holland America twice and for us, the food was a major upgrade. The buffet was actually really good and we liked it more than the dining room as you basically have service at the table and you are just in charge of getting your food.
We are sticking to Carnival and Holland America from now on.