My favorite sailing is Celebrity out of San Juan. For me, one of the best advantages of leaving from San Juan is that there are usually not as many sea days and more port days. As for Celebrity ships, they don't attract as many children as Royal would (I am a teacher and could only sail on school breaks). Unfortunately these days, Celebrity out of San Juan is too rare.
I actually don't "think" that, I know it for a fact. Was just on Millennium 2/18, brought 4-1 gallon bottles to check with my luggage (as I have done in the past) and was told they are not allowed to check it. I had to carry all 4 bottles on board with me. Not sure if it is a Celebrity rule or a Pan America rule, but it was definitely a rule.