(A little background which was probably assumed in the responses above Last I checked, both are Starwood properties (so consider SPG upgrades if you have those). I think Swan was originally branded a Sheraton and the Dolphin a Westin (I'm sure someone will correct me if I got those reversed). When they were originally built, Sheraton and Westin were not part of the same hotel group. I believe there are several other threads on this same topic, so you may want to search for additional comments. It's been a number of years since I stayed at either, but I don't remember much difference between them; assuming Dolphin is/was the Westin, I would probably have that as a first choice.