We do it frequently, but, we live only 45 minutes from HHI. We make an excuse to go to the island, and, just have to stop in and buy a Mickey Premium. You can eat at the Grill at the Pool if you want. We have been shown Grand Villas several times when we were planning a family trip (didn't work out all the same). A lot of time, it depends on how busy they are and who is in charge that day.
No matter what, go by the check-in. In the afternoon, they have cookies...GOOD cookies.
And look for Mike the Pool guy. He knows more about Hilton Head than just about anyone.