Both the Destiny and Inspiration came out in 1996. same age
Which port of call is better depends on the individual and varies according to what one does. When selecting a cruise one must first decide what their taste are
PAST TRIPS= Enchanted Capri
Carnival: Inspiration, Legend, Valor, Destiny, Holiday, Triumph, Splendor, Fantasy
HAL: Maasdam twice, Statendam, Oosterdam
Both ships from 1996. Inspiration is a Fantasy class. Destiny is the first of the 'all balcony' ships and is much larger. Ship would be the Destiny. Ports, GC same on both, Cozumel much better, more fun, more interesting, and not depressing like Jamaica. Been to Jamaica twice, did the falls, good. And been to MoBay. Since then have stayed on board in Jamaica. There is a feeling, an "air," of desperation and poverty in Jamaica. Doesn't jibe with a 'vacation'.
Coz., always enjoy the food, the sights, and the people.
Strictly my opinion.
While both cruises will have beautiful beaches and scenery, I would tend more towards the Cozumel and Grand Cayman because of the uniqueness of Cozumel. While Jamaica does have beautiful waterfalls and rainforests, the offerings between Ocho Rios and Grand Cayman are very similar. Cozumel offers the opportunity to visit Mayan ruins on the island, plus you can choose to visit Tulum or Coba(the only Mayan pyramid on the Yucatan people are still allowed to climb) on the mainland. Coba is only partially excavated and there is a cenote(underground water filled cavern) between Tulum and Coba for snorkeling or SCUBA diving(with open water cerification). The best way to choose is to explore guidebooks and shore excursions to find what you are interested in.
Ochos Rios and Grand Cayman are nothing alike. One is a very poor, 3rd world country and a very large, partly mountainous island.
Grand Cayman is a much smaller very upscale island still owned by Great Britain.
While Cozumel has a lot to do, trips to the mainland can be iffy, since travel time from Cozumel to and from the Mayan sites only allows a very short period of time to see them.
But to say that the two are similar and have similar offerings just means that you haven't been there....yet.
Carnival Destiny going to Ocho Rios Jamaica, and Grand Cayman Islands, Or Carnival Inspiration going to Cozumel Mexico, and Grand Cayman Islands?
Grand Cayman is my favorite port so far..... So you have that covered.
Cozumel is a great beach day port, with 20 or so beaches to choose from for every taste and need.
Ocho Rios was on our last cruise in Febraury and was by far our least favorite port so far. (Cabbies, vendors, store workers, everybody there is trying to seel you something in a ridiculously pushy manner. Makes Nassau vendors look like ghosts)
I would even prefer going to Freeport, before I ever book a cruise to Ocho Rios again.
We have already booked a cruise on the Inspiration to Grand Cayman and Cozumel because that is two of our favorite ports....
I would take Cozumel over Ocho Rios every single time.