Probably my last 60 cruises has been on RCCL. I've been on many Carnival cruises including the Inaugural Cruise for the Sensation circa 1990. Both lines have a lot to offer, IMHO. There isn't much different in the food quality, quantity or food service between the two lines. Staff is about the same with most being friendly and capable. We started on RCCL and just seemed to be more of what we were looking for like sniffing corks and such!
Bill