We stayed down the street at Chabil Mar but went to Turtle Inn twice for our "fancy" dinners - ie dinners where I wanted to wear one of the cute sundresses I packed.
I have worked in the high-end resort industry so I was also eager to see the decor. Love the space here - rustic, subtle but refined and stylish all the same. The food was outstanding. I had red snapper and we took advantage of pizza night on Sundays (buy 1 get the second for free).
The second visit my husband and I shared two pasta dishes - gnocchi and eggplant parm. Very very good - on par with some of the better Italian spots in NYC.
Note - TI has a vegetarian menu but we didn't realize this until our second visit. Be sure to request it if one of you is a veggie. Also note that part of the gratuity - 10% - is included.