Never actually stayed at Carambola but spent a day on their beach which was very nice (and so were the grounds). A couple I know who stayed there last year rated it decent (her) to very nice (him)... =)
I HAVE stayed at the Buccaneer (nice hotel with two great beaches and close to C'sted) as well as the more budget friendly Hotel on the Cay on an island in C'sted Harbor (a little run down but inexpensive with a central location). The latter is reached by a 3 min boat ride, so lugging dive gear plus having to park your rental on the street may be less desirable. On the flip side you can hit the bars and restaurants in C'sted and walk home.
Carambola is certainly remote from the broader range of wine and dine options in C'sted and out East (though Eats and Rowdy Joes in Cane Bay are great), but if your trip is mostly centered around diving you can easily drive to F'sted (the Pier is a must do dive), the walls off North Star/Cane Bay (shore dives), as well as Salt River marina to dive the canyon (boat dive).
Good luck
Rik