I visited St Thomas and stayed a week at the Ritz in January 2013. I thought the location of the hotel on St. Thomas was great. It was secluded but still convenient to Red Hook.
The grounds of the hotel were beautiful.. great views of St John. I thought the rooms were nice... but I should add, I was attending an event and didn't pay for the room (nice perk, eh?) so I can't really comment on the "value" of the rooms/resort.
I did a few dives with the onsite dive shop (Patagon) .. in general they go to dives sites close to the resort. If I were to return to the Ritz, I think I'd give the dive shop in Red Hook a try instead hoping for better dives sites and more variety.
I played tennis almost each day and the two courts were nice but there is some type of machinery (perhaps the AC units for the entire resort) adjacent to the courts and they were loud! I couldn't even hear my opponent across the court announce the score during the game... kinda odd for a property like the Ritz in a setting like the Caribbean.
I ate several meals on site and enjoyed the global dining place the best... decent food and I didnt think the cost was too bad for the Ritz.
Overall, a nice stay and great service. Everyone I encountered seemed friendly.