Just did a similar one in May on the Magic. I would put it in #2 spot with Alaska #1. We did Bonaire instead of Antigua.
The itinerary is more tiring than the Eastern, thanks to lots of ports - which just call you to do something.
We got to San Juan late the night before, so no tourist time - but I highly recommend adding in that extra day + night to get the minimum experience. Old San Juan is easy to see, even in your own - and doable in part of a day, if you are not a lingerer. It could also be visited the morning of boarding if you are staying there.
Another option is to visit on disembarkation day; you have nearly a full day - and then you could catch a morning flight the following day. So many times, there is a cost savings by doing this.
I would pick a late PAT and avoid standing outside in the heat (yes, it is hot, even in December; maybe it’s never cool-er). This is definitely not PC, but it is just that one block of time, and then you are on the ship.
I am looking forward to another cruise stop in San Juan - with enough daytime hours for an excursion to El Yunque. (I have been there for both day - my 1st visit and night).
The drawback to these itineraries is the airfare difference between >Orlando and >San Juan. But I still would consider this cruise again as an option. Next May’s itinerary looks spectacular (but we already have the Eastern booked in November

). Airport to Port is a shorter ride than MCO to PC.
Book your hotel early - even before you decide on the cruise - to get a good rate and date. The Sheraton Old Town is closing this year for renovations. We stayed by the airport at the Residence Inn (great pool for actual swimming - and was walkable to the beach). Next door was a Hampton Inn, with Embassy Suites nearby. Aloft, Hyatt House/Place? near the port were sold out when we were booking (5 weeks pre-cruise). The Hilton Caribe,
DCL’s partner hotel, gets a lot of mixed reviews - and has for years on TripAdvisor.
Uber is available around the area. Non-chain hotels, BNB, are located within Old SJ - with access to restaurants, drug stores…
Bon Voyage!