I found the food on Grand Princess to be blander than on any RCI cruise, the eclectic PC dining made having a pleasant dining relationship with tablemates impossible (booked at at traditional table for 8, no one (except us) there each night), The bar service was slow and the waiters somewhat surly when you flashed your soda card, the choice of "frozen thingees" was very limited each day, the shows were lackluster, the theater and show lounge were both very crowded, very early (hard to find a seat any later than 30 mins before a show), bar service in show lounge was terrible, art auctions pushed 24/7 (there were THREE "final auction--last chance"), and the ship was generally laid out in a peculiar manner (the southwest specialty restaurant has a main thoroughfare right thru the middle of it, for example), and most disappointing was the lido deck buffet--laid out so that there was always a traffic jam, food was only so-so, and so few ass't waiters that you were always having to go get your own drinks.
Now, this may sound like a whole lot of complaining, but these were just the specific items we noted. Did that make it a bad cruise? Nope. It was still a nice cruise. Were there things I liked better on the Grand Princess than on any RCI cruise? Sure. I liked the size and layout of the cabin, I liked the freshwater pools, I liked the fact that the (few, always filled with kids or teenagers) hot tubs were open later, I liked the price for the soda card, and the speed with which our luggage made it to the cabin. We thought that Sabatini's was wonderful. Would I go on Grand Princess again? If the price and itinerary were extra tempting, sure. On an even basis? Nope.
..Joanne