I have stayed both at the Marriott Frenchmen's Reef/ Morning Star and at the Rennaisance. Frenchmen's Reef and Morning Star are together, just outside of the capitol, Charlotte Amalie. Frenchmen's Reef is pretty much a standard resort hotel, with spectacular water and shore views and a restaurant with wall to wall windows overlooking the entry to St. Thomas' Charlotte Amalie Harbor. Morning Star has a little more luxurious rooms, with many "apartments". The facilities of Frenchmen's Reef are available to guests at both hotels. The beach, pool and other activities are in common. All the beaches on St. Thomas are public... the Morning Star Beach is one of the better ones (they are all good).
We also enjoyed the Rennaisance, which is about five miles outside of Charlotte Amalie. Good beach... and an even better beach just next to it, with outstanding snorkeling.
Hope this helps. Enjoy the vacation.