I own at Vistana and I'm also a
DVC Member. I bought into Vistana with a family member originally in '94. We have since taken over the deed completely because said family member does not travel that much any more. When we bought Vistana, Starpoints were not even an issue. Starwood didn't take over until about 1999/2000. We do use our week there every year---I own in the Fountains section and have the opportunity to do an internal Sheraton Vistana trade to the Beach Club villas on Hutchinson Island in southeast FL. This resort is right on the beach. We have been very pleased with Vistana---no major complaints.
I can honestly say I love the DVC a little more, but I don't have enough points to stay in a 2 bedroom for 7 nights in summer months. The most I can do is 4 or 5 depending on the resort. I can stay longer if I go in off-season of course. But because the weekend points are so high, I tend to stay at Vistana for 7 nights and then move over to DVC using the lower Sun-Thurs points.
I do have the option to convert my Fountains week at Vistana into Starpoints for a price. You can check that out here :
http://www.starwoodvo.com/enroll/vistanaplus/
I just haven't committed to this yet. But my suggestion would be to join TUG, as Tinkerbelloncapecod suggested. Best $15 I ever spent and yearly renewals are only $10. If you plan on buying Vistana mostly for trades, just know that most Orlando timeshares don't trade that well. When we bought Vistana, it was something we knew we'd use in FL. I have many family members within a 1-2 hour drive of WDW, so it made sense for us. But as a trade, there are better timeshares out there for that purpose. Orlando is just so over-developed with timeshares, thus making it fairly easy for people to trade into. If you really want to stick with Vistana and Starpoints for trade, see if you can make Harborside, Atlantis on Paradise Island your home resort. Not sure if they're sold out or not. But I know this is an easy internal trade within the Starpoints program.
If you just want a cheap, easy week for trading, also consider South African, Carolinas beach resort, Hawaii......these all usually have much stronger trading power than Orlando weeks. Again, please consider TUG---wealth of information there. Wish I had known about it before I bought. I'd say buy Vistana resale if you can and then convert into Starpoints for the fee if this is what you really want. Good luck.