Ha, lots of Barcelo Maya folks here. We actually did Barcelo Tropical (same resort) in 2006 for our honeymoon. I'd definitely recommend Riviera Maya over Cancun. Barcelo was fine for what it was, but you can get so much better if you spend a little more.
Since then we've been to Puerto Vallarta 4 times, and not sure we'd ever go back to the east coast. We love the atmosphere there, totally different than the Carribbean side. If you decide to look west, check out Casa Velas. They do have a Velas resort in Playa as well. We love Casa Velas as it's boutique (80 rooms), never full, and adults only. Sit down restaurant so no buffet. Food is 4*.