The choices of hotels reflect what kind of experience you expect out of your stay. Indeed, if you wish to experience more than just a lovely room, then the SLS offers service and rooms that go above and beyond the standard luxury experience at the Grand Hyatt.
If you are looking for more of a Residential style experience, the Rosewood at Baha Mar would be more suitable.
For me, I opted for the Grand Hyatt. Having stayed in other hotels from this chain, I know what to expect from the room.