I own a time share at the Grand Mayan. If you can upgrade to it, there are a few perks. Two pools are for GM only. If you view the map the two pool areas furthest from the beach are GM only. We enjoy going every year however, the beach access is horrible. There is now good access to the water, rock ledges abound. Don't golf, however the course looks great. There are plenty of great places to eat on site. We rent a car so I can get my dive time done.
Sorry for the hijack
I would recommend a trip to Cozumel. I dived with Aldora this past winter and the dives were very memorable. The dives off the mainland are not as great IMHO. The only difficulty is parking in Playa. You can't get closer than 1/2 mile from the pier for the ferry, so it makes it a little bit of a drag(pun intended) to get your gear moved,,,thank goodness for roller bags.
The summer is reported to be a great time to go there. The ocean is calmer and the dive crowds maybe a little less. Don't know, never gone in the summer, always excited about getting out of MT in the winter.
The Cenotes diving south of Playa is great. The caverns sport a variety of differing dives, each unique and beautiful.
Best wishes on your trip.
