We stayed at the iberostar in November 2008 and overall thought it was a nice resort. The staff, grounds, rooms and general facilities were very good. The food was terrible in our opinion. We have stayed at many AI resorts in other countries and have realistic expectations for food quality. We don't expect 5 star meals at AIs, but the food was well below our expectations. From what I understand this is to be expected at mexican AIs.
The beach itself was nice, but the sharp rocks near the shore don't make it easy to swim or access the water directly from the beach.
We did not dive with Dressel divers instead chose Dive with Alison. Would highly recommend Alison - reasonable prices and very personalized service. At most there were 8 divers on each trip.
I'm not sure if we will stay at Iberostar again, but would certainly consider it.