We stayed a the Sol Santa Maria (right next to the Melia SC) in April 2005. Those were the only two hotels there at that point, the rest were under construction.
The area itself is quite "empty", not a lot to see except one gas station with a cafe and a small airport. I would guess that eventually they will open flights directly into Cayo Santa Maria.
The Sol was absolutely beautiful. Great beach (bit windy), good food and staff.
The nearby town of Caibarién (about 50 km) is wonderful to visit and get a taste of REAL CUBAN living.
There is another hotel called Villa las Brujas on the connecting cayo las Brujas which is interesting to visit. It is not in the travel mags. however it is a charming little hotel with individual bungalows that rent for about US$60/nt. not AI. We met lots of people to stay there that are simply travelling thru Cuba by car. It has an unbelievable beach. Worth a visit or a stay.
Check it out at the following link:
http://www.netssa.com/lasbrujas.html I am actually considering trying to convince my family to simply fly to Santa Clara and stay at this resort.
I would recommend this area.
Happy Travels