My wife and I have been to both Playa and Cancun with another couple the last four years, but we usually go in June. This year our schedule has us going the first week in September to the Riu Cancun. What is September like compared to June? I'm guessing since school will have started in the states that there will be less younger kids. We are late 20s early 30s so we like a lively crowd but not "Spring Break" lively. Anyone have any thoughts?