We visited Sanya in Hainan Island - the "Hawaii of China" - for 4 days. We started off at the Holiday Inn in Sanya Bay - gorgeous property and we got the executive suite thanks to Joon's connections but we ended up moving to the Marriott in Yalong Bay because the Inn's bed was too hard. And the hotels at Yalong Bay were fabulous. We went to Nanshan Buddhist Cultural Park and saw the 108 meter tall statue. We also looked at some real estate but decided it was too much trouble to purchase. Finally, we explored the hotels at Yalong Bay on a tandem bike.
In short, weather was good; beach was awesome (sand like silt); hotels were beautiful. But service needs more training (common experience in China), food was mediocre (surprising), and no nightlife to speak of.