Four Seasons is on Nevis not St. Kitts but I heard that it is absolutely stunning. Haven't seen it since its reopening but heard it is wonderful. The beach there was nothing wonderful but the Ritz's beach in STT is not glorious either - both on the small side! Golf availability is big difference! Ritz on East End of STT with easy accessibility to Red Hook for dining options and ferry to St. John and BVI. Ritz on STT overlooks Pillsbury Sound and the infinity pool there makes it seem like you can swim to St. John. Don't know when your honeymoon is but Ritz is doing some construction and building a Ritz Club right next door which will give access to a great beach! All rooms hillside with great views! Maybe someone who has been since Four Seasons rebuilt can fill in the details there!

We have been to the Four Seasons on Nevis two times both before the rebuilding. It is a wonderful place to go with nice amenities. My husband golfed which he said was nice and the course led you through parts of the rain forest where there were monkey's. We also went on a kitchen tour which was interesting. We did not leave the resort and I remember the beach being nice but nothing spectacular and they also have a few different water sports available. Overall it is a very QUIET vacation and there is not much to do after dinner. It takes awhile to reach the island as we flew into St. Kitt's then shuttled down to a boat that brought you right to the resort.The boat ride was very rough one day and takes around a half hour to reach the resort. On a calm day the ride was fun as they had refreshments and you could get a nice overview of the island on the approach. Staff meets you on the dock to welcome you and whisk you off to your room. Typical Four Seasons service.
Haven't been to the Ritz on Saint Thomas as we went 14 years ago and that wasn't there but Nevis and St. Thomas are two very different islands. Saint Thomas is very busy, lots of places to eat and shopping is a major attraction. Nevis is the complete opposite. We stayed at Caneel Bay on Saint John 14 years ago and it is still one of our favorite vacations - the beaches are gorgeous and so private- have you looked into that? Good luck!