We have dined on the Galaxy and the Sovereign of the Seas. I beleive the food aboard the Galaxy was better overall than the RCCL fare.
However, I cannot say that the difference was so great that I would alter itinerary for the food, and for me, as for so many others, food is very important. Even if the overall quality on RCCL is not up th the Celebrity quality that does not mean that you cannot find something that you like to eat, and no one goes hungry on a cruise.
Moreover, I have every expectation that since RCCL now owns Celebrity, the quality of the food for the separate cruise lines will dovetail in the future. It would be nice to think that the quality of RCCL would rise to that of Celbrity, but when the corporate heads start pinching pennies and charging you for a milkshake at Johnny Rockets, I have to be pessimistic.