We have done both itineraries.
We have done 7 day Mexican cruise from Long Beach (April 2012), and the 5 day Mexican cruise from San Diego (March, 2019), both on the Wonder. We have also sailed the Wonder from Vancouver to Alaska (July 2013).
Took the 7 day Western Caribbean cruise from Port Canaveral (December 2015) on Fantasy. We did not stop in Jamaica, but had an extra day at sea.
Mexico stops: We enjoyed Ensenada, even though there is not much there. It was very quaint. We also thought Puerto Vallarta had great food! We haven't had good look in Cabo - Easter week, they wouldn't let cruise passengers on their beaches, and we had such bad weather last time we were there that none of the local boat trips were operating.
Western Caribbean stops: We liked Cozumel - did Mr. Santos, and once (on another cruise line) went to Mayan ruins at Tulum - very interesting. Grand Cayman is beautiful, but we found it to be expensive, and pretty crowded on the beaches. I have been twice to Jamaica and I am OK if I never go there again.
We love all of the ships and I have sailed each of them multiple times (Magic - 2 ; Fantasy - 3; Wonder - 3; Dream - 11).
Wonder:
Pros: Larger adult pool. Great staff. Walt Disney Theatre and adult night time entertainment venues are all at the front of the ship
Cons: Less designated adult space
Magic:
Pros: More varied itineraries. More entertainment for longer itineraries. Larger adult pool
Cons: Food quality in MDRs is lousy. Staff is not quite as magical as on the other
DCL ships. Less designated adult space
Dream:
Pros: Good food. Convenient itineraries, several with two stops at
Castaway Cay. Lots of adult-only spaces
Cons: Smaller adult pool. Limited entertainment due to shorter voyages. Non-descript adult night time entertainment area. Walt Disney Theatre is at front of ship and adult night time venues are at back of ship
Fantasy:
Pros: Decent assortment of itineraries. Lots of adult only spaces. Interesting adult night time entertainment area
Cons: Smaller adult pool. Walt Disney Theatre is at front of ship and adult night time venues are at back of ship