I have stayed at all of them and, as a hotel (in terms of finish and service), I like FL best by far: it feels more elegant and sophisticated. The 2 bedroom condos are excellent and they also have oceanfront rooms that are around 600 sq feet. Key Biscayne is more of a resort hotel for families and doesn't have a road between itself and the beach. I do like the residences at Key Biscayne, but I didn't feel comfortable there (a "mixed" clientele shall I say?) and the pool service was extremely poor! Als bear in mind that, at Key Biscayne, you must drive to get anywhere - though Biscayne Bay is a pleasant area. Palm Beach - I just don't like the RC (then again I don't rate FS or the Breakers either!); it has a very pinched feel on its land, so the pool area easily gets packed.