So this was my first trip to Mexico but I did a TON of research...as I usually do because it passes for entertainment for me. In general Mexico is not a great beach place. There are resorts with decent beaches but often the water is very rough and not good for swimming. In terms of food it's always going to be better in Mexico over the DR or Cuba. The more southern Caribbean islands will also have good food and beaches but the prices are going to be very high....ie:$2500+ pp. A co-worker of DH has just left for two weeks in Playa Del Carmen and he has rented a condo there for only $600/week. DH said it looks really nice. We went into Playa Del Carmen for an afternoon and I saw a huge grocery store just outside of the main tourist area. Playa is now pretty 'American-ized'...they have
Walmart, Home Depot, Sam's Club, Costco etc etc. It's only about 40-45 minutes away from Cancun airport and you can get private airport transfers for about $90CAD RT. If this sort of thing interests you get on the TripAdvisor forums and start reading. There is a large community on there of people that like to do the rental thing. Lots of info there on things to do, places to go, dining and so on.
I don't know specifically about that Iberostar but generally that chain is good. Others big chains to look at are RIU, Ocean, Princess, and Barceló. My other options for this trip were the Grand Sirenis and the Barceló. I would also go to the Valentin Imperial....it gets VERY high praise as being a lot of bang for the buck. Anything in the Barceló complex might tick off a lot of your boxes.