In addition to
DVC, we also own at the Westin St. John. The timeshare section is VERY small, and the members tend to use the points to stay at their home resort, so it is very difficult to get into. That is why we purchased at the Westin, because we fell in love with the island on a
Disney cruise and knew we wanted to go back on a regular basis. At the time, it wasn't available as a DVC trade, but when it became available, even our DVC sales rep said it would be near impossible to trade into through DVC, and I guess she was right.
I agree that the beach is not that great, but as another poster pointed out, the island is full of some of the nicest beaches in the world. So even if the beach at the Westin was better, it would still make sense to explore the other beaches on the island.
In response to the comment that it does not compare to DVC, what other timeshare does? Westin is in the process of upgrading their timeshare rooms. On our first visit, we stayed in one of the unrenovated rooms and it in NO WAY compared to DVC. On the second trip we were in a renovated room, and it was beautiful, quite the equal to DVC. Granite counter tops in the kitchen and bathrooms, beautiful tiles, fine furnishings, flat screen tv and Bose sound system, etc.
Also, we like the fact that the resort is across the street from the main resort and up on a hill. It keeps the timeshare section nice and peaceful, while providing great views of the bay. There are two quiet pools in the timeshare section, and we were usually the only ones in the pool when we used them. And the three bedrooms each have their own private pool, with sliding glass doors that open the living room up to the patio. Very nice. The main resort area is a short 5 minute walk away (but the walk back is MUCH more difficult because of the steep hill) and there is always the hotel shuttle service to take you to and from the main section of the resort if you want. The shuttle picks you up and drops you off at your room.
As for other islands to try, have you considered Aruba? We have never been, but we have heard some great things. And if you are not particular about where you stay, there are a number of resorts to trade into, which would increase your chances of success.
And even if you aren't able to trade into the Westin St. John, I would still strongly suggest you get to the island one of these days (if you haven't been already). There are many different types of places to stay on the island if you are willing to pay cash, from campgrounds to luxury private homes. It REALLY is a special place.