RGF:
I've cruised Celebrity each of the past two Decembers (on Galaxy & Summit) and had an excellent experience each time. My wife and sons (ages 13 & 16) thoroughly enjoyed it as well. We found the food, service, accomodations and activities quite good.
Unfortunately, we booked Alaska for this August but needed to cancel because of sports commitements, decided on Carribbean again in December aboard Millenium.