I used to live on Hilton Head. I can tell you anything you want to know. I have been there - not stayed the night - but have been to the resort about 100 times. They have only one quick service dining option. Its by the pool and gift shop. Its very small. Hilton Head is about a 8 x 12 mile island shaped like a tennis shoe. The island is divided into plantation. Sea Pines - the most popular has Harbor Town which is what you see if you watch golf and the Heritage Tournament. Known for the lighthouse. Any way, there are restaurants there, like the Salty Dog Cafe, Personally is Beach Slop in my book but the tourists really like it. Im sure you have seen everyone wearing that tshirt. There is shopping to do and some dining in Harbor Town. You can rent boats and go dolphin watching and play golf and tennis. That is pretty much all there is to do on Hilton Head. Some plantations are just residential. Others, have things to do. Where Disney is located, its outside a plantation and next to a place called Shelter Cove. It, much like Harbor Town but with out the $5 fee to get into the plantation, has restaurants and shopping and is part of a marina. Disney is not beach front. It is on the marsh side. They have a shuttle bus that takes you to the ocean beach side. If you want something to eat besides the one quick service restaurant, you have to walk to Shelter Cove by the footbridge and path. The food at the quick service is okay. Typical. If you want a good list of restaurants on the Island, I can provide you that list. You will need a car for most of them. There is a bar area called the Bar-Muda triangle. Cheesy but true. It's mostly old guys there on golf weekends in Hawaiian shirts and sun burns trying to pick up local girls or girls on spring break.
As for things to do, after 2 1/2 years on the island, basically there is only golf, tennis, beach and more golf. There are a few putt putt places - 1 good and 2 okay. The Disney Resort is run much like the others at WDW. Very nice but pricey for what you get in my opinion. You can rent bikes and they do have fun activities planned by Disney. From a resort level, on par with all Disney Resorts. As for activities and things to do on HHI...meh, not much to do. If you want any additional info, let me know.
If you are a golfer or tennis and beach goer - this would be the place for you.