we went to an all inclusive in the mayan riviera. I had been to Europe with some people who had lived there and were fluent...worldly travelers. It was fine, but not something I'd have been comfortable doing alone. I'm not ready for a bRainman- Madagascar spear fishing expedition.
We did the all inclusive and I liked it. There were hands out for tips, even though there weren't supposed to be, the extra tours like snorkeling(sucked for us...like an ironman swim, not snorkeling) Mayan ruins and things like that cost $50-$100 each.
I had some family recently return from some island off Beliz that swear its the way to go.
Drinks were free, but a lot of them were screwed up....green maruarita mix in a bloody mary....stuff like that.