We stayed at the Island House Hotel, and almost gave the restaurant a miss because the idea seemed lazy, with so much to explore on the island. I'm so glad we ended up here!
We had excellent service, the best view in the restaurant (we made a reservation for 6pm, as soon as the restaurant opens), and all 4 of us raved about our meals. The steak au poivre (pepper steak) was reportedly " the most tender steak [my father-in-law] has had in a long time", the white fish was fresh and very good, the perch was reportedly cooked perfectly (hubby's only complaint was that the breaking wasn't very crispy), and I loved he mushroom risotto. The Brussels sprouts were FANTASTIC.
If you're not going to be the first in the restaurant, you probably will still have a decent view. However, consider making a reservation and asking if they'll hold he center window table for you. It's a spectacular view.
PS...the wine list is pretty solid.