First stay at the Mandarin Oriental and was amazed at the service. This was the best service received at a hotel in the U.S.
Example: the concierge recommended an off-property restaurant that would be suitable for my 2 yr old son, husband and I, and once we were seated at said restaurant, the manager brought us a glass of champagne each courtesy of the hotel concierge. There were a few other instances like this in our very short stay.
Other five star things besides service: rooms, view, breakfast buffet.
Four star: pool, location.
Location, while not perfect, was actually quite convenient.
Definitely would stay again.