I hate Cancun and will never go back, but we enjoyed the Sheraton there. We stayed there a few years ago at Christmas and despite the hotel being sold out and the fact that I took 3 rooms on points for my family, they gave me plat upgrades for all the rooms to the top floor of the towers, ocean view rooms with balconies. My family members were pretty impressed (of course, we often get plat upgrades to suites that are much better than even these rooms with Starwood, and might have gotten one of the ones with a hot tub on it's balcony at the Sheraton Cancun had we booked only one room and not 3).
I did not like the restaurants at the Sheraton at all. But the hotel service was good, rooms were very nice, location was good, and if I liked Cancun I would not hesitate to stay there again. But not liking Cancun I won't be back. I'd muhc rather stay in a cheap hotel or guest house in one of the towns south of Cancun.