You asked for how long to stay - personally we can't stay shorter than five days and we typically like to stay seven. (If points allowed, I'd stay longer)!!
HHI is a relaxed family oriented resort with loads of activities at the resort itself plus a whole island filled with boating, kayaking, tennis, golf, horsebackriding, mini-golf, shopping, swimming, sailing, biking, and of course there really awesome beach. Our family LOVES HHI and returns there every summer for a fun filled sun soaked week.
There are restaurants galore all over the island as well as grocery stores to stock your villa.
The cm's at HHI are the BEST!! Really, I mean that. The recreational staff plans lots of fun activities for kids, teens, and family groups and they are just very friendly and super helpful.