It wasn't mia reef at that point, but it was nice. It's got its own private island, with a nice beach that only hotel guests can use.
If you want to do touristy stuff in Cancun, don't stay on Isla. It's a lot of time going back and forth to the mainland.
When we stayed there, we did one day trip to Tulum and xel- ha. If you want a relaxing, hang out on the beach vacation, Isla is great. Super quiet, calm, good snorkeling.