Did not cruise, but spent a long weekend in San Juan about a month ago. We stayed in Condado nearby, so know nothing about the hotels there.
Old San Juan (where the cruise ships dock) is quaint, lots of shops and narrow streets to stroll down. Hotels are all old and in former churches and museums and such. Amazing amount of Designer fashion shops all over San Juan - even in Condado among century old hurricane ruins! Small flea market area in the center of town. Lots of museums, churches, art to see.
There are two old forts on either side of town that are cool to see. But beware - they try to sell you a dual ticket to both forts for like $5 - cheap. OK we went for it. When you finish the inland fort San Cristóbal they tell you to walk around the corner and up the hill, follow the walkway to the other one - which is MILES away! When it finally comes into view, you see that it is another MILE out a grassy knoll, then you play mountain goat up stairways inside. Luckily there is a movie in the a/c first or we would have DIED! Someone, do this thing with a pedometer. I'd love to know how many miles we actually trudged. Well worth seeing, but man! They tell you there is nowhere to park at the 2nd one, but there is some on the streets much closer than walking all the way - in very humid weather. Suggest you do just the one with the grassy knoll - El Morro.
Anyhoo, the Bicardi distillery is supposed to be a great tour. We intend to do that one when we do a cruise that stops there. We were beat every afternoon and I actually lost weight on a vacation rather than gained!