We have sailed the Explorer twice and love this ship! It's easy to get around, the staff is wonderful, the food is awesome and the kids activities ROCK! We can't get our kids out of there, even if we paid them!!!
Our last cruise was a 12 day and San Juan was one of our favorites. Enough so that the kids want to go back and just "do" the town! They are 11 and then 8.
Given the chance we would/will cruise again on the Explorer. Dh wants to do the New England cruise again so it will be on our agenda of "want tos" soon.