I have had questions about Cancun vs. Mayan Riviera.

Cancun, we more or less know about it. It is a strip of land lodeged between two bodies of water, and full of great hotels. A lot of action. Busy.

Mayan Riviera is down South from Cancun on the coast, and it much more sparsely populated. You typically get all inclusive secluded resorts. Mayan Riviera is very close to the ecoparks, e.g. Xel Ha.

So what works for you? For me, I like the action Cancun offers. But you have to be careful with the beaches in Cancun. They got very rocky since the last hurricane, and although hotels try their best to cover the rocks with sand, it is not always a success story. So do check the beach conditions in your hotel.

Mayan Riviera on the other hand is protected by the Island of Cozumel from the worst hurricanes have to offer. so I think you will have a better luck there.