Depends what you are looking for. Beach villas at the Ritz are much better than the St. Regis. However, The St. Regis Overwater Suites cannot be beaten.

I've stayed in both last year and had a wonderful time at the St. Regis, 15 nights total and was sad to go. Then moved to the Ritz for 4 nights but left after 2 nights only as the place was very much lacking service issues all over the place.

I'm returning to the Ritz this May for a week. If you have never been to the St. Regis, then it is a must.