We just returned from the Casa Magna Cancun and the entire family LOVED IT!!! (Mom, Dad, 6, 9, 12 yr old, and grandma) The staff was great and the place is incredibly KID FRIENDLY!!! The views are great as well. The lobby is large and beautiful. The atmosphere is relaxed.
The breakfast buffet was huge and fresh. Try to get a package that includes it. The whole family loved Mikado as well. They also have Dominos inside the hotel which made our 9 and 12 year olds happy.
And there is more beach here than most of the hotels in Hotel Zone. We know because we walked it.
The location is quiet but only minutes from the nightlife (rain forest cafe and Señor Frogs) Aqua World is almost across the street for all your water activities and Wet and Wild is 15 minutes south and we recommend it for swimming with the dolphins and the water slides and food and drink are included. It was very fun!!! Tulum is a must do for the history and beautiful setting and it has a beach below the temple for cooling off. Find one of the taxi drivers who has a suburban to quote prices. The same drivers are always out front of the hotel. Anyway enjoy now because Cancun was not crowded!