We really enjoyed our stay at Villa Cannatelli, the location is beautiful and very peaceful. The area has good walking opportunities and staying on the terrace or by the pool was extremely relaxing. Also convenient for driving to Porto S. Stefano, the lagoon at Orbetello, the beach and nature reserve at La Feniglia, sightseeing in Grosseto and the Roman ruins at Ansedonia. We didn't have much luck visiting beaches around Argentario however, as the access to most of them seemed to be privately owned.
Regarding the Villa, the kitchen was small, but well-equipped and cooking was not a problem. We also used the barbecue one evening. Beds and chairs etc. were comfortable. When we had a couple of small problems (with the AC and a shower tap), Rita dealt with them immediately. She also provided a lot of assistance when we had issues with our car hire, which was greatly appreciated.
The only think that might be noted is that the access can be tricky. The road leading past the drive is steep and narrow and was challenging for a large car. Other than this, we were very very pleased with our stay and would definitely recommend.