I've never been to the Caribbean but I've been to Playa Del Carmen and I love it there and would be going again this year except its Disney's year (we try to alternate).
I went the AI route so I don't know too much about the restaurants there, but I did see a lot of the usuals (Carlos N Charlies, Senor Frogs, Mc Donalds, Subway, etc.). There were also plenty of local places, but we didn't try any.
We stayed at the Playacar Palace which is right next door to Fifth Avenue, the shopping district. Not alot of malls ala Cancun, but plenty of shops from high end to low end. It's a closed street and you just walk from shop to shop. Fifth Avenue is also where many of the restaurants and bars are.
At the end of Fifth Avenue is the ferry to Cozumel. Nice for a day trip. There's nice snorkling and scuba diving there and more shopping, but not too much night life.
I don't know much about the other resorts in the area as we always stay at a Palace Resort (
www.palaceresorts.com). They have three hotels in the hotel zone in Cancun and one just outside the airport and one in Cozumel. If you stay at a Palace resort, you can visit any other resort. I believe there is another in Playacar or very close, but it was adults only so we didn't visit. The stay at one, play at all came in handy when visiting Cozumel as the resort can serve as a temporary home base.
I think the Playacar Palace would be good for your age group. It is very quiet and doesn't have the party atmosphere like Cancun. There are nightly shows and theme nights. Three restaurants (Asian, Italian (table service) and Mexican buffet). There are four bars (poolside, swimup, lobby and a lounge open at night).
Hope this helps.
