Can't help you, but I can say that you will have a great time. The swmbo and I just came back from a dive trip in Playa 2 months ago! We spent 9 days there, and are dying to go back!
Also, if you make it through Play del Carmen, check out Bad Boys on the beach. It's a great place for some live music/cheap fizzy mexican beers http://badboysbeachbar.com/.