We got back from Vieques three weeks ago, and if you're planning a trip there, I'd highly recommend staying at the Hacienda Tamarindo.
Great staff, nice rooms, along with the perfect pool, views, and breakfasts.
We're pretty picky about where we stay,and the Hacienda ranks right up there.
The food we had on Vieques was really good. We aren't big fusion-gourmet "dining" types, however. The skirt steak -(churrasco)- at the Island Steak House was great. It's the restaurant at The Crow's Nest. You should definitely go there.
In Esperanza, the Tradewinds is pretty good. I thought that Bili was kind of so-so, but maybe it was what I ordered. We ended up going to Bananas (also in Esperanza, on the waterfront) a lot for lunch because the fish sandwiches with homemade potato chips were "Over the Top" - just Excellent.
We heard great things about Chez Shack, on the Hix House road, from two groups of people we talked to, but we didn't make it over there.
We never did eat dinner in Isabel Segundo either, but a couple of places there were highly recommended by Burr Vail, the owner of Hacienda Tamarindo.