Thanks to all who answered my questions. Here is a very quick report of our STT time:
Used the CA ferry from St. J and would recommend this to anyone making the transition and staying at the Frenchman's Reef/ Morningstar property. Its a bit more expensive than Red Hook, but more convenient.
Our stay at the Marriott was a mixed bag- we liked the look of the place(s) and enjoyed being beachfront for our stay ( Morningside) but found the staff almost brusque, the check-in process confusing and not well organized, and the housekeeping to be suspect.
The water sport staff was very nice, and the non-Marriott employees ( at the jewelry shops and the Sand Bar and Havana Blue) were lovely.
Its an easy beach to manage- pretty wide and not steep for water entry. The sand is soft and though there is some grass accumulation at the ends and a few places where the rocks gather all in all its great for relaxing on a float or just standing around.
Morningstar seems to cater more to adults, and families seem to gravitate to the main facility, but both have their share of large "convention groups".
We didn't spend as much time exploring this island as we did St. J, but we found CA an interesting place to walk around and offering plenty of dining options...but jewelry shops are everywhere and the hands down winner for sheer numbers.
The detractor for town was the number of hawkers who try to engage you to shop in "their" stores...they are fairly persistent, but not intimidating like the ones we experienced in Mexico.
Had dinners at Havana Blue and Room With a View, enjoyed both and felt "Room" to be the better value; lunches at Gladys' which was wonderful and the Marriott Beach Bar which was marginal due to indifferent service and just average food. Only breakfast was again at the beach bar and again a disappointing experience.
Nice big room with GREAT balcony to enjoy, but thin walls and "exuberant" neighbors made sleeping a little tough. Not sure that the housekeepers were trying too hard as trash that was on the stair when we arrived was still there when we left and the balcony wasn't swept, but nothing stood out as problematic.
Would probably not choose this place again, but wouldn't deter others who think they'd like to try it.